Open Quantum Frontier Institute Workshop

Introduction

We are pleased to invite you to the 1st Workshop of the Open Quantum Frontier Institute, which will take place at the Colorado School of Mines in Golden, CO on February 21-22, 2020. The purpose of the workshop is to advance quantum information research in noisy and open quantum systems and build quantum engineering education programs throughout the U.S. Our two-day workshop will feature:

  • Invited talks given by professors, postdocs, and senior researchers
  • Posters presented by postdocs, graduate, and undergraduate students
  • Poster award
  • Student travel support (TBD)
  • Catered lunch and coffee breaks

For more information, please contact quantum@mines.edu.

Registration Information

Our workshop is open for broad participation and can support up to 180 attendees.

Online registration closed on February 19, 2020. You may still be able to register. Please contact us at quantum@mines.edu.

Conference Location

Friday 2/21 and Saturday 2/22, Green Center Metals Hall, Colorado School of Mines

Schedule

Date, TimeActivity
Friday 2/21
08:00-09:00 AM Registration, Breakfast, Coffee
09:00-09:15 AMLincoln Carr Welcoming Remarks
Oral Session I
Quantum Simulations
Mina Fasihi, Chair
25 min talk, 5 minutes for questions
09:15-09:45 AMHilary Hurst, Joint Quantum Institute/San Jose State University

Quantum Control with Spinor Bose-Einstein Condensates

Understanding and controlling many-body quantum systems in noisy environments is paramount to developing robust quantum technologies. An external environment can be thought of as a measurement reservoir which extracts information about the quantum system. Cold atoms are well suited to examine system-environment interaction via weak (i.e. minimally destructive) measurement techniques, wherein the measurement probe acts as the environment and also provides a noisy record of system dynamics. The measurement record can then be used in a feedback scheme, opening the door to real time control of quantum gases. In this talk I discuss our theoretical proposal to use weak measurement and feedback to engineer new phases in spin-1/2 Bose-Einstein condensates. We show that measurement and feedback alters the effective Hamiltonian governing system dynamics, thereby driving phase transitions reminiscent of a quantum quench for the closed system. We also develop a feedback cooling protocol which prevents runaway heating of the condensate due to measurement backaction. Our results show that measurement and feedback can alter condensate dynamics in a stable, controllable manner and provides a route toward Hamiltonian engineering in many-body systems. Finally, I will discuss ongoing experimental work to realize our proposal using Rb87.

Speaker Bio: Hilary Hurst received her BS in Engineering Physics from the Colorado School of Mines. She went on to earn a Masters in Theoretical Physics at the University of Cambridge and received her PhD in physics from the University of Maryland. She is currently an NRC Postdoctoral Fellow at NIST and the Joint Quantum Institute and will be joining the faculty at San Jose State University in the Fall. Her areas of research include quantum measurement and feedback control for many-body systems and magnetization dynamics in dissipative systems.
09:45-10:15 AMRichard T. Scalettar, University of California Davis

Quantum Simulation Studies of Charge Patterns in Fermi-Bose Systems

The Holstein Model describes the interaction between fermions and a collection of local (dispersionless) phonon modes, and has intimate connections to the attractive Hubbard Hamiltonian. In the dilute limit, the phonon degrees of freedom dress the fermions, giving rise to polaron and bipolaron formation. At higher densities, the phonons mediate collective superconducting (SC) and charge density wave (CDW) phases. I will review the basic physics of the Holstein model and show results of some recent Quantum Monte Carlo (QMC) simulations where we have determined the quantum critical point and finite temperature transition points of the Holstein model on a honeycomb lattice, and also on the role of phonon dispersion on SC and CDW order. I will conclude the presentation by discussing a new, Langevin-based, algorithm which might allow connections to cold atom quantum simulators of Bose-Fermi mixtures.

Speaker Bio: Richard Scalettar received his PhD in physics in 1986 from the University of California, Santa Barbara. In 1989, after a post-doc in the Chemistry Department at the University of Illinois, Urbana-Champaign, he joined the Physics faculty at the University of California, Davis. Prof. Scalettar's research is in the application of Quantum Monte Carlo methods to problems in quantum magnetism, superconductivity, and localization. He was elected Fellow of the American Physical Society in 2004, and served as chair of the APS Division of Computational Physics in 2010. In 2009, he received the Chancellor's Outstanding Undergraduate Mentor Award at UC Davis, and in 2014 was named as an outstanding referee of the American Physical Society.
10:15-10:30 AM Coffee and Snacks
Oral Session II
Quantum Computing 1
Matthew Jones, Chair
10:30-11:00 AMZhexuan Gong, Colorado School of Mines

Speed limit of entangling gates in quantum computers: Theory and Experiment.

Fast two-qubit entangling gates are essential for quantum computers with finite coherence times. Due to the limit of interaction strength among qubits, there exists a theoretical speed limit for a given two-qubit entangling gate. This speed limit has been explicitly found only for a two-qubit system and under the assumption of negligible single qubit gate time. We propose to demonstrate such speed limit experimentally using two superconducting transmon qubits with an always-on capacitive coupling. Moreover, we investigate a modified speed limit when single qubit gate time is not negligible, as in any practical experimental setup. Finally, we study the generalization to multiple qubit systems where the coupling to additional qubits can significantly increase the speed limit of a two-qubit entangling gate, thus requiring the co-design of the quantum computer from both theorists and experimentalists for optimal gate performance.

Speaker Bio: Zhexuan Gong received his PhD in Physics from the University of Michigan in 2013. He was then a postdoctoral research associate and research scientist at the Joint Quantum Institute, University of Maryland and NIST. He joined Mines in 2018 as an assistant professor and also holds a NIST associate position. His areas of research include quantum computing, quantum information theory, and quantum many-body physics.
11:00-11:30 AMXiao Mi, Google

Quantum supremacy using a programmable superconducting processor

The promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here we report the use of a processor with programmable superconducting qubits to create quantum states on 53 qubits, corresponding to a computational state-space of dimension 253 (about 1016). Measurements from repeated experiments sample the resulting probability distribution, which we verify using classical simulations. Our Sycamore processor takes about 200 seconds to sample one instance of a quantum circuit a million times—our benchmarks currently indicate that the equivalent task for a state-of-the-art classical supercomputer would take approximately 10,000 years. This dramatic increase in speed compared to all known classical algorithms is an experimental realization of quantum supremacy for this specific computational task, heralding a much-anticipated computing paradigm.

Speaker Bio: Xiao is an experimental physicst at Google working on quantum gate metrology and applications of near-term quantum processors to condensed matter physics problems. Prior to joing Google, Xiao pioneered the integration of circuit quantum electrodynamics with semiconductor spin qubits during his PhD at Princeton. He is the recipient of the 2020 Richard Greene Condensed Matter Thesis Prize from the American Physical Society.
Oral Session III
Open Quantum Systems
Tyjal Dewolf-Moura, Chair
11:30-12:00 PMEliot Kapit, Colorado School of Mines

Noise-tolerant quantum speedups in quantum annealing without fine tuning

Quantum annealing is a powerful alternative model for quantum computing, which can succeed in the presence of environmental noise even without error correction. However, despite great effort, no conclusive proof of a quantum speedup (relative to state of the art classical algorithms) has been shown for these systems, and rigorous theoretical proofs of a quantum advantage generally rely on exponential precision in at least some aspects of the system, an unphysical resource guaranteed to be scrambled by random noise. In this work, we propose a new variant of quantum annealing, called RFQA, which can maintain a scalable quantum speedup in the face of noise and modest control precision. Specifically, we consider a modification of flux qubit-based quantum annealing which includes random, but coherent, low-frequency oscillations in the directions of the transverse field terms as the system evolves. We show that this method produces a quantum speedup for finding ground states in the Grover problem and quantum random energy model, and thus should be widely applicable to other hard optimization problems which can be formulated as quantum spin glasses. Further, we show that this speedup should be resilient to two realistic noise channels (1⁄f-like local potential fluctuations and local heating from interaction with a finite temperature bath), and that another noise channel, bath-assisted quantum phase transitions, actually accelerates the algorithm and may outweigh the negative effects of the others. The modifications we consider have a straightforward experimental implementation and could be explored with current technology.

Speaker Bio: Eliot Kapit receieved his PhD from Cornell in 2012. From there, he did postdocs at Oxford and the City University of New York, before starting as an Assistant Professor of Physics at Tulane University from 2015-2018. In summer 2018, he joined the faculty of Colorado School of Mines. His research focuses on quantum information, many-body physics, and novel superconducting circuits.
12:00-12:30 PMTimur Tscherbul, University of Nevada Reno

Quantum coherence from thermal noise: From coherent dynamics to non-equilibrium steady states

Quantum coherence is widely regarded as an essential resource for quantum information processing and quantum sensing. In this talk, I will present an overview of our recent work on the quantum dynamics of noise-induced Fano coherences that occur in multilevel quantum systems interacting with a thermal bath (such as blackbody radiation) in the absence of coherent driving. By solving the nonsecular Bloch-Redfield quantum master equation for a model three-level V-system driven by a thermal bath, we show that Fano coherences exhibit quantum beats when the spacing between the excited states of the V-system is large compared to the radiative decay rates. In the opposite limit of small excited-state spacing, we observe the emergence of non-equilibrium quasi-steady states, which become true non-equilibrium steady states if the thermal driving is polarized. The general theory will be illustrated with two examples involving the time evolution of Fano coherences in Rydberg atoms immersed in blackbody radiation and the breaking of detailed balance in atomic calcium driven by polarized incoherent light. Implications of these results for quantum information processing and quantum thermodynamics will be discussed.

Speaker Bio: Tscherbul Timur earned his PhD from Moscow State University, and received a Killam postdoctoral fellowship at the University of British Columbia. He joined the faculty at the University of Nevada, Reno in 2015 after working as a postdoc at Harvard and the University of Toronto. He is a computational quantum physisist interested in the theory of open quantum systems, quantum dynamics and control of complex atomic and molecular systems, quantum impurity problems, and diagrammatic Monte Carlo methods.
12:30-01:30 PM Catered Lunch
Oral Session IV
Quantum Computing 2
Kirsten Blagg, Chair
01:30-02:00 PMJustin Johnson, National Renewable Energy Lab

Molecular approaches to robust qubits: theory, structures, and spectroscopy

The versatility of chemical substitution provides nearly infinite space for controlling energy levels and electronic/spin population flow in conjugated organic molecules, and as such, excited-state molecular systems may lend themselves robust qubits with unique properties. We have chosen to investigate the spin states of triplet exciton pairs that are generated quickly upon photoexcitation of tailored molecules and appear to be protected from decoherence even at room temperature until decay to the ground state on a microsecond timescale. Strong spin polarization seems inherent in some of these systems, as detected through the distinct pattern of microwave absorption in a static magnetic field (i.e., EPR spectra). Furthermore, some molecules produce photon emission that is dependent on the exact spin state, much like nitrogen vacancy in diamond systems where magnetic resonance is detected optically. We are a building a library of molecules that can be coupled to each other with tunable strengths and geometries in order to understand the fundamental properties of spin-entangled triplet pairs, and more incisively to evaluate whether or not there might be inherent advantages of this approach, especially in terms of sensitivity to noise, compared with more conventional open quantum systems. This is an early stage and focused effort, but we hope to make connections to other work to uncover synergies or extensions of our ideas and capabilities that impact QIS more broadly.

Speaker Bio: Justin Johnson has been a senior scientist at the National Renewable Energy Laboratory (NREL) since 2008 and is also a joint appointee in Chemistry at Colorado School of Mines. He received his Ph.D. in Chemistry from the University of California, Berkeley, in 2004 and subsequently did postdoctoral work with Dr. Arthur Nozik at NREL and Prof. Josef Michl at the University of Colorado, Boulder. His technical expertise is in ultrafast and nonlinear spectroscopy, and his research interests include investigating the dynamics of photophysical phenomena associated with solar light harvesting, energy storage, and quantum information in both molecular and nanoscale semiconductor systems.
02:00-02:30 PMRaymond Simmonds, National Institute of Standards and Technology

Manipulating mechanical and electrical quanta with parametric circuits

Parametric processes are ubiquitous in nature. At their heart is an interaction that involves a nonlinear relationship between changing quantities. These processes can lead to energy transport in different forms. One form produces amplification, like the well -known example of a child on a swing who periodically changes her center of gravity causing the resonance frequency of the swing to be modulated, inducing more swinging. Here, energy from her pumping legs at one frequency is absorbed and transferred into more motion at a different swinging frequency. This type of phenomenon can be mechanical (as with a swing) or electrical in nature, lending itself to many useful technological applications. Parametric processes are paramount for new emerging quantum information technologies like laser-cooled trapped ions, linear quantum optics, or opto-mechanics. Analogous physical systems can be created on a single chip using superconducting circuits, along with nonlinear Josephson junctions, or metalized flexible membrane capacitors. In this talk, I will discuss our experimental efforts at NIST to utilize parametric interactions to help control different physical processes that are important manipulating quantum information. Harnessing these processes on-chip with superconducting circuit components, including micro-drum mechanical resonators, electromagnetic cavity modes, and superconducting quantum bits provides a highly programmable platform for engineering both closed and open quantum systems for simulation or computation.

Speaker Bio: Ray Simmonds received his BA, MA, and PhD from the University of California, Berkeley in 2002, where he studied Quantum Interfrence in superfluid He-3. After a 2 year post-doc at NIST in Boulder CO developing superconducting quantum bits, he became a staff physicist. His current research is focused on the application of superconducting microwave and optomechanical circuit techniques for quantum information, measurement, and computing.
02:30-03:00 PM Coffee and Cookies
03:00-06:00 PMOpen Quantum Frontier Institute Strategy Meeting and Breakout Sessions
Saturday 2/22
08:00-09:00 AMBreakfast, Coffee
08:50 AM Opening Remarks
Oral Session V
Materials for Quantum Information Science
Edwin Supple, Chair
09:00-09:30 AMTzu-Ming Lu, Sandia National Lab

Hole spins in Ge/GeSi heterostructures

There is growing interest in leveraging the unique properties of hole-carrier systems and their intrinsically strong spin-orbit coupling to engineer novel qubits. For example, qubit controls using electric dipole spin resonance have recently been demonstrated in Ge/GeSi hole quantum dots. In this talk, we will present unique physical properties of holes in Ge/GeSi heterostructures as well as our ongoing efforts toward hole spin qubits, including development of gated device architectures, charge sensing, and magneto-spectroscopy in the few-hole regime. We will also present our theoretical understanding and modeling of electric dipole spin resonance of holes in Ge quantum dots through intrinsic spin-orbit coupling. An effective two-level Hamiltonian for the spin of an individual hole is derived from the strain of the heterostructure and electrostatic potential, allowing for predictions on how the spin will respond to applied AC fields. Acknowledgements: This work was funded, in part, by the Laboratory Directed Research and Development Program and performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the US Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in this article do not necessarily represent the views of the US Department of Energy or the United States Government. The work at NTU was supported by the Ministry of Science and Technology (107-2622-8-002-018-).

Speaker Bio: Tzu-Ming Lu received his B.S. from National Taiwan University in 2004 and Ph.D. from Princeton University in 2011. After graduate school, he was a postdoctoral researcher at Sandia National Laboratories, New Mexico, where he is currently a Senior Member of Technical Staff. His research topics include semiconductor device physics, spin-orbit coupling in solid-state systems, and quantum behavior of nanoscale structures. He is also a Center for Integrated Nanotechnologies (CINT) scientist, supporting user projects on quantum information science and solid-state physics at the nanoscale.
09:30-10:00 AMRupert Lewis, Sandia National Lab

Reversible Superconducting Logic for Low Power Computation

Reversible computing is the ultimate low energy computing technology. To be reversible, a computational operation must not only be able to run forward or backward but must preserve the energy of a bit. In practice, performing logic operations at or below the Landauer limit of kBT ln2 per logical operation is the goal of the field. Superconducting circuits are the perfect technology for implementing ballistic reversible circuits due to inherently low losses and the use of single flux quanta as robust bits. I will discuss our progress towards an asynchronous ballistic reversible logic based on fluxons propagating along superconducting lines and incorporating Josephson junctions as active elements. While superconducting logic families have the long-term potential of transforming high performance computing such as data centers, in the near term, the greatest impact is likely to be on quantum computers where the low energy dissipation (relative to transistorized logic) will enable in cryostat control of quantum computers. Funding Statement: Supported by the LDRD program at SNL, a multi-mission laboratory managed and operated by NTESS, LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. DOE’s NNSA under contract DE-NA0003525.

Speaker Bio: Rupert Lewis received his PhD from Indiana University in 2001. He completed post-docs at the National High Magnetic Field Lab (in Tallahassee) and at the the University of Maryland where he worked on such diverse subjects as Wigner crystalization of 2D electron systems and superconducting implementations of quantum computing. Recently, he's branched out into reversible computing. He's been a staff member at Sandia since 2013.
10:00-10:30 AM Corey Rae McRea, National Institute of Standards and Technology

The Boulder Cryogenic Quantum Testbed

The investigation of materials losses at low powers and temperatures has been identified as critical for increasing performance and scalability of superconducting quantum computers. This investigation requires the dissemination of a community standard for the accurate and repeatable measurement and analysis of superconducting microwave resonators. JILA / CU’s Boulder Cryogenic Quantum Testbed (CQT) is a non-profit, pre-competitive research facility for developing and openly disseminating standard protocols to reproducibly measure the quality factor and performance characteristics of superconducting microwave resonators used in quantum computing circuits. The testbed was founded on a philosophy of open collaborative science by a joint initiative between government, academic, and industry partners.

Speaker Bio: Corey Rae McRae received her PhD in Quantum Information from the University of Waterloo in 2018. She is now a postdoctoral researcher at the National Institute of Standards and Technology Boulder, as well as the director of the Boulder Cryogenic Quantum Testbed at JILA, University of Colorado Boulder. She studies materials losses in superconducting quantum circuits as well as the behavior and performance of superconducting microwave resonators.
10:30-11:00 AMCoffee and Snacks
Oral Session VI
Quantum Measurement and Sensing
Joel Howard, Chair
11:00-11:30 AMKater Murch, Washington University

Superconducting quantum circuits: exploring frontiers of quantum measurement and dissipation at microwave frequencies

Josephson junction based quantum circuits have enabled broad exploration into open quantum systems in the microwave frequency domain. The combination of coherent quantum bits, robust single qubit control, and quantum noise limited parametric amplifiers has yielded an unprecedented view into the physics of quantum measurement and quantum dissipation. I will survey a range of research topics that are currently open to experimental exploration with this platform, including weak measurement and quantum trajectories, non-Markovian dynamics, effective non-Hermitian dynamics, quantum thermodynamics, and quantum sensing.

Speaker Bio: Kater Murch received his PhD in physics in 2008 from the University of California, Berkeley, with disseration research focusing on cold atom cavity QED and measurement backaction. His postdoctoral work at UC Berkeley focused on superconducting quantum circuits and quantum measurement. Since 2014, he has been at Washington University in St. Louis with work focusing on open quantum systems experiment with superconducting circuits. Kater has received an Alfred P. Sloan fellowship, an NSF CAREER award, and a Cottrell Scholar award.
11:30-12:00 PMPauli Kehayias, Sandia National Lab

Magnetic sensing using nitrogen-vacancy centers in diamond

Nitrogen-vacancy (NV) centers in diamond have gained much recent interest for their uses in magnetic sensing and quantum information. NV centers are fluorescent defect centers that have discrete electronic states with few-millisecond lifetimes, can be optically initialized and read out, are magnetically sensitive, and work in ambient conditions or extreme environments. Furthermore, our ability to place NV centers near the diamond surface (as close as a few nanometers) enables us to have a small separation between the NVs and external magnetic field sources, allowing us to sense external sources with high spatial resolution and sensitivity. After introducing NV DC and AC magnetometry techniques, I will present some ongoing NV magnetic sensing applications, including small-volume NMR spectroscopy, magnetometry and pressure sensing in a diamond anvil cell, and magnetic microscopy for geology, biology, and condensed-matter physics.

Speaker Bio: Pauli did his PhD work at UC Berkeley, after which he was a postdoc at Harvard. Currently he is a Truman Fellowship postdoc at Sandia National Labs. He works on magnetic sensing and imaging with nitrogen-vacancy centers in diamond, with applications in NMR spectroscopy, paleomagnetism, biomagnetism, and magnetic materials.
12:00-01:00 PM Catered Lunch and Breakout Session
Oral Session VII
Quantum Education
Casey Jameson, Chair
25 min talk, 5 minutes for questions
01:00-01:30 PMMark Beck, Reed College

Exploring Fundamentals of Quantum Mechanics with Optics

Individual photons and entangled-photon pairs are excellent resources for exploring fundamental questions in quantum mechanics. We, and others, have developed a number of teaching laboratories that use these resources to do precisely that. The experiments include: "Proving" that light consists of photons, single-photon interference, and tests of local realism. I will describe some of these experiments, as well as the physics behind them. I will also describe our recent work on experiments that involve more than two photons.

Speaker Bio: Mark Beck received his BS and PhD degrees in Optics from the University of Rochester. He was a postdoctoral researcher at the University of Oregon, and has taught physics at Reed College and Whitman College since 1994. His areas of research specialization are quantum optics and quantum measurement. In 2018 he was the recipient of the Richtmyer Memorial Lecture Award from the American Association of Physics Teachers.
01:30-02:00 PMTheresa Lynn, Harvey Mudd College

Quantum Secrets: Protecting Them in the Laboratory, Unraveling Them in the Classroom

I report on aspects of quantum education at Harvey Mudd beyond the quantum mechanics course sequence for physics majors. In upper-level physics labs, for example, entangled photon experiments allow direct experimental investigation of phenomena central to quantum information, while NMR experiments give students valuable exposure to working with pulse sequences and the language of coherence times. In introductory courses, principles of quantum mechanics have been presented in the contexts of quantum optics and of materials science at both the first-semester and sophomore levels. And outside the major, our undergraduate quantum information course relies on linear algebra but minimal background in physics, and regularly enrolls the majority of its students from outside the physics major (chiefly computer science and math majors). Time permitting, I will supplement this overview of quantum education at Harvey Mudd with some recent undergraduate research in my quantum optics group, where our work focuses on non-ideal situations involving entanglement. In one project, we measure photon pairs partially entangled in polarization to show that certain partially entangled states have a surprising one-way feature in the way that measurements on one particle non-classically alter the measurement statistics of the second (EPR steering). In another project, we have established several limits on how well non-entangling measurements can perform generalized Bell measurements on entangled states more complex than the two-qubit case; these limits are relevant to recent and near-term experimental realizations of quantum teleportation and dense coding protocols.

Speaker Bio: Theresa Lynn received her B.A. in physics from Harvard and did her Ph.D. at Caltech doing experimental quantum optics and atomic physics. After working as a postdoc and staff scientist at Caltech in educational outreach and nuclear astrophysics, Theresa returned to AMO physics when she took a faculty position at Harvey Mudd College, where she has been since 2006. Her current research areas are quantum optics and fundamentals of quantum mechanics. Since 2014 she has taught an introductory quantum information course to an audience of physics and other STEM majors.
02:00-04:00 PM

Poster Session with Coffee and Cookies

Kirsten Blagg
Colorado School of Mines
Thermoelectric Effects in Superconductor Ferromagnetic Hybrids

Jacob Cutshall
Reed College
A New Form of Quantum Tomography

Mina Fasihi
Colorado School of Mines
Complex Network Description of Phase Transitions in the Classical and Quantum Disordered Ising Model

Patrick Harrington
Washington University St. Louis
Photonic Transport in Quantum Metamaterials

Joel Howard
Colorado School of Mines
Investigating Entanglement Rates of Coupled Superconducting Qubits

Eric Jones
Colorado School of Mines
Variational Preparation of Quantum Hall States on a Lattice

Matthew Jones
Colorado School of Mines
Open Source Matrix Product States: A Simulation Platform for Quantum Computing Technologies

Daria Kowsari
Washington University St. Louis
Memory in Non-Markovian Open Quantum Systems

Suyesh Koyu
University of Nevada Reno
Quantum Coherent Dynamics from Thermal Noise: A Three-level V-system Driven by Incoherent Radiation

Joshua Lewis
Colorado School of Mines
Use of Fractional Calculus in the Analysis of Quantum Systems

Alex Lidiak
Colorado School of Mines
Quantum State Compression and Analysis via Dimensionality Reduction

Bradley Lloyd
Colorado School of Mines
Quantum Dots in Silicon as a Candidate Platform for Scalable Quantum Computing and Quantum Neuromorphic Devices

Nick Materise
Colorado School of Mines
Quantum Heat Engine Simulated on Superconducting Qubits

David Rodriguez Perez
Colorado School of Mines
Variable Dissipation in Small Logical Qubits

Zhijie Tang
Colorado School of Mines
Theoretical Survey of Unconventional Quantum Annealing Methods Applied to a Difficult Trial Problem

Brooks Venuti
Colorado School of Mines
Probing Magnetic Skyrmions in the Presence of Disorder
04:00-04:30 PM Poster Awards, Final Remarks. Workshop ends for most participants
04:30-05:00 PM Breakout Session Summaries: Recommendations for QLCI Proposal
05:00-06:00 PM Open Quantum Frontier Institute Strategy Closed Meeting

Invited Speakers

Speaker/Inst/Abstract/Bio
Mark Beck, Reed College

Exploring Fundamentals of Quantum Mechanics with Optics

Individual photons and entangled-photon pairs are excellent resources for exploring fundamental questions in quantum mechanics. We, and others, have developed a number of teaching laboratories that use these resources to do precisely that. The experiments include: "Proving" that light consists of photons, single-photon interference, and tests of local realism. I will describe some of these experiments, as well as the physics behind them. I will also describe our recent work on experiments that involve more than two photons.

Speaker Bio: Mark Beck received his BS and PhD degrees in Optics from the University of Rochester. He was a postdoctoral researcher at the University of Oregon, and has taught physics at Reed College and Whitman College since 1994. His areas of research specialization are quantum optics and quantum measurement. In 2018 he was the recipient of the Richtmyer Memorial Lecture Award from the American Association of Physics Teachers.
Hilary Hurst, Joint Quantum Institute/San Jose State University

Quantum Control with Spinor Bose-Einstein Condensates

Quantum Control with Spinor Bose-Einstein Condensates

Understanding and controlling many-body quantum systems in noisy environments is paramount to developing robust quantum technologies. An external environment can be thought of as a measurement reservoir which extracts information about the quantum system. Cold atoms are well suited to examine system-environment interaction via weak (i.e. minimally destructive) measurement techniques, wherein the measurement probe acts as the environment and also provides a noisy record of system dynamics. The measurement record can then be used in a feedback scheme, opening the door to real time control of quantum gases. In this talk I discuss our theoretical proposal to use weak measurement and feedback to engineer new phases in spin-1/2 Bose-Einstein condensates. We show that measurement and feedback alters the effective Hamiltonian governing system dynamics, thereby driving phase transitions reminiscent of a quantum quench for the closed system. We also develop a feedback cooling protocol which prevents runaway heating of the condensate due to measurement backaction. Our results show that measurement and feedback can alter condensate dynamics in a stable, controllable manner and provides a route toward Hamiltonian engineering in many-body systems. Finally, I will discuss ongoing experimental work to realize our proposal using Rb87.

Speaker Bio: Hilary Hurst received her BS in Engineering Physics from the Colorado School of Mines. She went on to earn a Masters in Theoretical Physics at the University of Cambridge and received her PhD in physics from the University of Maryland. She is currently an NRC Postdoctoral Fellow at NIST and the Joint Quantum Institute and will be joining the faculty at San Jose State University in the Fall. Her areas of research include quantum measurement and feedback control for many-body systems and magnetization dynamics in dissipative systems.
Justin Johnson, National Renewable Energy Lab

Molecular approaches to robust qubits: theory, structures, and spectroscopy

The versatility of chemical substitution provides nearly infinite space for controlling energy levels and electronic/spin population flow in conjugated organic molecules, and as such, excited-state molecular systems may lend themselves robust qubits with unique properties. We have chosen to investigate the spin states of triplet exciton pairs that are generated quickly upon photoexcitation of tailored molecules and appear to be protected from decoherence even at room temperature until decay to the ground state on a microsecond timescale. Strong spin polarization seems inherent in some of these systems, as detected through the distinct pattern of microwave absorption in a static magnetic field (i.e., EPR spectra). Furthermore, some molecules produce photon emission that is dependent on the exact spin state, much like nitrogen vacancy in diamond systems where magnetic resonance is detected optically. We are a building a library of molecules that can be coupled to each other with tunable strengths and geometries in order to understand the fundamental properties of spin-entangled triplet pairs, and more incisively to evaluate whether or not there might be inherent advantages of this approach, especially in terms of sensitivity to noise, compared with more conventional open quantum systems. This is an early stage and focused effort, but we hope to make connections to other work to uncover synergies or extensions of our ideas and capabilities that impact QIS more broadly.

Speaker Bio: Justin Johnson has been a senior scientist at the National Renewable Energy Laboratory (NREL) since 2008 and is also a joint appointee in Chemistry at Colorado School of Mines. He received his Ph.D. in Chemistry from the University of California, Berkeley, in 2004 and subsequently did postdoctoral work with Dr. Arthur Nozik at NREL and Prof. Josef Michl at the University of Colorado, Boulder. His technical expertise is in ultrafast and nonlinear spectroscopy, and his research interests include investigating the dynamics of photophysical phenomena associated with solar light harvesting, energy storage, and quantum information in both molecular and nanoscale semiconductor systems.
Eliot Kapit, Colorado School of Mines

Noise-tolerant quantum speedups in quantum annealing without fine tuning

Quantum annealing is a powerful alternative model for quantum computing, which can succeed in the presence of environmental noise even without error correction. However, despite great effort, no conclusive proof of a quantum speedup (relative to state of the art classical algorithms) has been shown for these systems, and rigorous theoretical proofs of a quantum advantage generally rely on exponential precision in at least some aspects of the system, an unphysical resource guaranteed to be scrambled by random noise. In this work, we propose a new variant of quantum annealing, called RFQA, which can maintain a scalable quantum speedup in the face of noise and modest control precision. Specifically, we consider a modification of flux qubit-based quantum annealing which includes random, but coherent, low-frequency oscillations in the directions of the transverse field terms as the system evolves. We show that this method produces a quantum speedup for finding ground states in the Grover problem and quantum random energy model, and thus should be widely applicable to other hard optimization problems which can be formulated as quantum spin glasses. Further, we show that this speedup should be resilient to two realistic noise channels (1⁄f-like local potential fluctuations and local heating from interaction with a finite temperature bath), and that another noise channel, bath-assisted quantum phase transitions, actually accelerates the algorithm and may outweigh the negative effects of the others. The modifications we consider have a straightforward experimental implementation and could be explored with current technology.

Speaker Bio: Eliot Kapit receieved his PhD from Cornell in 2012. From there, he did postdocs at Oxford and the City University of New York, before starting as an Assistant Professor of Physics at Tulane University from 2015-2018. In summer 2018, he joined the faculty of Colorado School of Mines. His research focuses on quantum information, many-body physics, and novel superconducting circuits.
Pauli Kehayias, Sandia National Lab

Magnetic sensing using nitrogen-vacancy centers in diamond

Nitrogen-vacancy (NV) centers in diamond have gained much recent interest for their uses in magnetic sensing and quantum information. NV centers are fluorescent defect centers that have discrete electronic states with few-millisecond lifetimes, can be optically initialized and read out, are magnetically sensitive, and work in ambient conditions or extreme environments. Furthermore, our ability to place NV centers near the diamond surface (as close as a few nanometers) enables us to have a small separation between the NVs and external magnetic field sources, allowing us to sense external sources with high spatial resolution and sensitivity. After introducing NV DC and AC magnetometry techniques, I will present some ongoing NV magnetic sensing applications, including small-volume NMR spectroscopy, magnetometry and pressure sensing in a diamond anvil cell, and magnetic microscopy for geology, biology, and condensed-matter physics.

Speaker Bio: Pauli did his PhD work at UC Berkeley, after which he was a postdoc at Harvard. Currently he is a Truman Fellowship postdoc at Sandia National Labs. He works on magnetic sensing and imaging with nitrogen-vacancy centers in diamond, with applications in NMR spectroscopy, paleomagnetism, biomagnetism, and magnetic materials.
Rupert Lewis, Sandia National Lab

Reversible Superconducting Logic for Low Power Computation

Reversible computing is the ultimate low energy computing technology. To be reversible, a computational operation must not only be able to run forward or backward but must preserve the energy of a bit. In practice, performing logic operations at or below the Landauer limit of kBT ln2 per logical operation is the goal of the field. Superconducting circuits are the perfect technology for implementing ballistic reversible circuits due to inherently low losses and the use of single flux quanta as robust bits. I will discuss our progress towards an asynchronous ballistic reversible logic based on fluxons propagating along superconducting lines and incorporating Josephson junctions as active elements. While superconducting logic families have the long-term potential of transforming high performance computing such as data centers, in the near term, the greatest impact is likely to be on quantum computers where the low energy dissipation (relative to transistorized logic) will enable in cryostat control of quantum computers. Funding Statement: Supported by the LDRD program at SNL, a multi-mission laboratory managed and operated by NTESS, LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. DOE’s NNSA under contract DE-NA0003525.

Speaker Bio: Rupert Lewis received his PhD from Indiana University in 2001. He completed post-docs at the National High Magnetic Field Lab (in Tallahassee) and at the the University of Maryland where he worked on such diverse subjects as Wigner crystalization of 2D electron systems and superconducting implementations of quantum computing. Recently, he's branched out into reversible computing. He's been a staff member at Sandia since 2013.
Tzu-Ming Lu, Sandia National Lab

Hole spins in Ge/GeSi heterostructures

There is growing interest in leveraging the unique properties of hole-carrier systems and their intrinsically strong spin-orbit coupling to engineer novel qubits. For example, qubit controls using electric dipole spin resonance have recently been demonstrated in Ge/GeSi hole quantum dots. In this talk, we will present unique physical properties of holes in Ge/GeSi heterostructures as well as our ongoing efforts toward hole spin qubits, including development of gated device architectures, charge sensing, and magneto-spectroscopy in the few-hole regime. We will also present our theoretical understanding and modeling of electric dipole spin resonance of holes in Ge quantum dots through intrinsic spin-orbit coupling. An effective two-level Hamiltonian for the spin of an individual hole is derived from the strain of the heterostructure and electrostatic potential, allowing for predictions on how the spin will respond to applied AC fields. Acknowledgements: This work was funded, in part, by the Laboratory Directed Research and Development Program and performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the US Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in this article do not necessarily represent the views of the US Department of Energy or the United States Government. The work at NTU was supported by the Ministry of Science and Technology (107-2622-8-002-018-).

Speaker Bio: Tzu-Ming Lu received his B.S. from National Taiwan University in 2004 and Ph.D. from Princeton University in 2011. After graduate school, he was a postdoctoral researcher at Sandia National Laboratories, New Mexico, where he is currently a Senior Member of Technical Staff. His research topics include semiconductor device physics, spin-orbit coupling in solid-state systems, and quantum behavior of nanoscale structures. He is also a Center for Integrated Nanotechnologies (CINT) scientist, supporting user projects on quantum information science and solid-state physics at the nanoscale.
Theresa Lynn, Harvey Mudd College

Quantum Secrets: Protecting Them in the Laboratory, Unraveling Them in the Classroom

I report on aspects of quantum education at Harvey Mudd beyond the quantum mechanics course sequence for physics majors. In upper-level physics labs, for example, entangled photon experiments allow direct experimental investigation of phenomena central to quantum information, while NMR experiments give students valuable exposure to working with pulse sequences and the language of coherence times. In introductory courses, principles of quantum mechanics have been presented in the contexts of quantum optics and of materials science at both the first-semester and sophomore levels. And outside the major, our undergraduate quantum information course relies on linear algebra but minimal background in physics, and regularly enrolls the majority of its students from outside the physics major (chiefly computer science and math majors). Time permitting, I will supplement this overview of quantum education at Harvey Mudd with some recent undergraduate research in my quantum optics group, where our work focuses on non-ideal situations involving entanglement. In one project, we measure photon pairs partially entangled in polarization to show that certain partially entangled states have a surprising one-way feature in the way that measurements on one particle non-classically alter the measurement statistics of the second (EPR steering). In another project, we have established several limits on how well non-entangling measurements can perform generalized Bell measurements on entangled states more complex than the two-qubit case; these limits are relevant to recent and near-term experimental realizations of quantum teleportation and dense coding protocols.

Speaker Bio: Theresa Lynn received her B.A. in physics from Harvard and did her Ph.D. at Caltech doing experimental quantum optics and atomic physics. After working as a postdoc and staff scientist at Caltech in educational outreach and nuclear astrophysics, Theresa returned to AMO physics when she took a faculty position at Harvey Mudd College, where she has been since 2006. Her current research areas are quantum optics and fundamentals of quantum mechanics. Since 2014 she has taught an introductory quantum information course to an audience of physics and other STEM majors.
Corey Rae McRea, National Institute of Standards and Technology

The Boulder Cryogenic Quantum Testbed

The investigation of materials losses at low powers and temperatures has been identified as critical for increasing performance and scalability of superconducting quantum computers. This investigation requires the dissemination of a community standard for the accurate and repeatable measurement and analysis of superconducting microwave resonators. JILA / CU’s Boulder Cryogenic Quantum Testbed (CQT) is a non-profit, pre-competitive research facility for developing and openly disseminating standard protocols to reproducibly measure the quality factor and performance characteristics of superconducting microwave resonators used in quantum computing circuits. The testbed was founded on a philosophy of open collaborative science by a joint initiative between government, academic, and industry partners.

Speaker Bio: Corey Rae McRae received her PhD in Quantum Information from the University of Waterloo in 2018. She is now a postdoctoral researcher at the National Institute of Standards and Technology Boulder, as well as the director of the Boulder Cryogenic Quantum Testbed at JILA, University of Colorado Boulder. She studies materials losses in superconducting quantum circuits as well as the behavior and performance of superconducting microwave resonators.
Xiao Mi, Google

Quantum supremacy using a programmable superconducting processor

The promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here we report the use of a processor with programmable superconducting qubits to create quantum states on 53 qubits, corresponding to a computational state-space of dimension 253 (about 1016). Measurements from repeated experiments sample the resulting probability distribution, which we verify using classical simulations. Our Sycamore processor takes about 200 seconds to sample one instance of a quantum circuit a million times—our benchmarks currently indicate that the equivalent task for a state-of-the-art classical supercomputer would take approximately 10,000 years. This dramatic increase in speed compared to all known classical algorithms is an experimental realization of quantum supremacy for this specific computational task, heralding a much-anticipated computing paradigm.

Speaker Bio: Xiao Mi is an experimental physicst at Google working on quantum gate metrology and applications of near-term quantum processors to condensed matter physics problems. Prior to joing Google, Xiao pioneered the integration of circuit quantum electrodynamics with semiconductor spin qubits during his PhD at Princeton. He is the recipient of the 2020 Richard Greene Condensed Matter Thesis Prize from the American Physical Society.
Kater Murch, Washington University

Superconducting quantum circuits: exploring frontiers of quantum measurement and dissipation at microwave frequencies

Superconducting quantum circuits: exploring frontiers of quantum measurement and dissipation at microwave frequencies

The combination of coherent quantum bits, robust single qubit control, and quantum noise limited parametric amplifiers has yielded an unprecedented view into the physics of quantum measurement and quantum dissipation. I will survey a range of research topics that are currently open to experimental exploration with this platform, including weak measurement and quantum trajectories, non-Markovian dynamics, effective non-Hermitian dynamics, quantum thermodynamics, and quantum sensing.

Speaker Bio: Kater Murch received his PhD in physics in 2008 from the University of California, Berkeley, with disseration research focusing on cold atom cavity QED and measurement backaction. His postdoctoral work at UC Berkeley focused on superconducting quantum circuits and quantum measurement. Since 2014, he has been at Washington University in St. Louis with work focusing on open quantum systems experiment with superconducting circuits. Kater has received an Alfred P. Sloan fellowship, an NSF CAREER award, and a Cottrell Scholar award.
Richard T. Scalettar, University of California Davis

Quantum Simulation Studies of Charge Patterns in Fermi-Bose Systems

Quantum Simulation Studies of Charge Patterns in Fermi-Bose Systems

The Holstein Model describes the interaction between fermions and a collection of local (dispersionless) phonon modes, and has intimate connections to the attractive Hubbard Hamiltonian. In the dilute limit, the phonon degrees of freedom dress the fermions, giving rise to polaron and bipolaron formation. At higher densities, the phonons mediate collective superconducting (SC) and charge density wave (CDW) phases. I will review the basic physics of the Holstein model and show results of some recent Quantum Monte Carlo (QMC) simulations where we have determined the quantum critical point and finite temperature transition points of the Holstein model on a honeycomb lattice, and also on the role of phonon dispersion on SC and CDW order. I will conclude the presentation by discussing a new, Langevin-based, algorithm which might allow connections to cold atom quantum simulators of Bose-Fermi mixtures.

Speaker Bio: Richard Scalettar received his PhD in physics in 1986 from the University of California, Santa Barbara. In 1989, after a post-doc in the Chemistry Department at the University of Illinois, Urbana-Champaign, he joined the Physics faculty at the University of California, Davis. Prof. Scalettar's research is in the application of Quantum Monte Carlo methods to problems in quantum magnetism, superconductivity, and localization. He was elected Fellow of the American Physical Society in 2004, and served as chair of the APS Division of Computational Physics in 2010. In 2009, he received the Chancellor's Outstanding Undergraduate Mentor Award at UC Davis, and in 2014 was named as an outstanding referee of the American Physical Society.
Raymond Simmonds, National Institute of Standards and Technology

Manipulating mechanical and electrical quanta with parametric circuits

Parametric processes are ubiquitous in nature. At their heart is an interaction that involves a nonlinear relationship between changing quantities. These processes can lead to energy transport in different forms. One form produces amplification, like the well -known example of a child on a swing who periodically changes her center of gravity causing the resonance frequency of the swing to be modulated, inducing more swinging. Here, energy from her pumping legs at one frequency is absorbed and transferred into more motion at a different swinging frequency. This type of phenomenon can be mechanical (as with a swing) or electrical in nature, lending itself to many useful technological applications. Parametric processes are paramount for new emerging quantum information technologies like laser-cooled trapped ions, linear quantum optics, or opto-mechanics. Analogous physical systems can be created on a single chip using superconducting circuits, along with nonlinear Josephson junctions, or metalized flexible membrane capacitors. In this talk, I will discuss our experimental efforts at NIST to utilize parametric interactions to help control different physical processes that are important manipulating quantum information. Harnessing these processes on-chip with superconducting circuit components, including micro-drum mechanical resonators, electromagnetic cavity modes, and superconducting quantum bits provides a highly programmable platform for engineering both closed and open quantum systems for simulation or computation.

Speaker Bio: Ray Simmonds received his BA, MA, and PhD from the University of California, Berkeley in 2002, where he studied Quantum Interfrence in superfluid He-3. After a 2 year post-doc at NIST in Boulder CO developing superconducting quantum bits, he became a staff physicist. His current research is focused on the application of superconducting microwave and optomechanical circuit techniques for quantum information, measurement, and computing.
Timur Tscherbul, University of Nevada Reno

Quantum coherence from thermal noise: From coherent dynamics to non-equilibrium steady states

Quantum coherence from thermal noise: From coherent dynamics to non-equilibrium steady states

Quantum coherence is widely regarded as an essential resource for quantum information processing and quantum sensing. In this talk, I will present an overview of our recent work on the quantum dynamics of noise-induced Fano coherences that occur in multilevel quantum systems interacting with a thermal bath (such as blackbody radiation) in the absence of coherent driving. By solving the nonsecular Bloch-Redfield quantum master equation for a model three-level V-system driven by a thermal bath, we show that Fano coherences exhibit quantum beats when the spacing between the excited states of the V-system is large compared to the radiative decay rates. In the opposite limit of small excited-state spacing, we observe the emergence of non-equilibrium quasi-steady states, which become true non-equilibrium steady states if the thermal driving is polarized. The general theory will be illustrated with two examples involving the time evolution of Fano coherences in Rydberg atoms immersed in blackbody radiation and the breaking of detailed balance in atomic calcium driven by polarized incoherent light. Implications of these results for quantum information processing and quantum thermodynamics will be discussed.

Speaker Bio: Tscherbul Timur earned his PhD from Moscow State University, and received a Killam postdoctoral fellowship at the University of British Columbia. He joined the faculty at the University of Nevada, Reno in 2015 after working as a postdoc at Harvard and the University of Toronto. He is a computational quantum physisist interested in the theory of open quantum systems, quantum dynamics and control of complex atomic and molecular systems, quantum impurity problems, and diagrammatic Monte Carlo methods.
Zhexuan Gong, Colorado School of Mines

Speed limit of entangling gates in quantum computers: Theory and Experiment.

Fast two-qubit entangling gates are essential for quantum computers with finite coherence times. Due to the limit of interaction strength among qubits, there exists a theoretical speed limit for a given two-qubit entangling gate. This speed limit has been explicitly found only for a two-qubit system and under the assumption of negligible single qubit gate time. We propose to demonstrate such speed limit experimentally using two superconducting transmon qubits with an always-on capacitive coupling. Moreover, we investigate a modified speed limit when single qubit gate time is not negligible, as in any practical experimental setup. Finally, we study the generalization to multiple qubit systems where the coupling to additional qubits can significantly increase the speed limit of a two-qubit entangling gate, thus requiring the co-design of the quantum computer from both theorists and experimentalists for optimal gate performance.

Speaker Bio: Zhexuan Gong received his PhD in Physics from the University of Michigan in 2013. He was then a postdoctoral research associate and research scientist at the Joint Quantum Institute, University of Maryland and NIST. He joined Mines in 2018 as an assistant professor and also holds a NIST associate position. His areas of research include quantum computing, quantum information theory, and quantum many-body physics.

Poster Session

NameInstPoster Title
Kirsten BlaggMinesThermoelectric effects in Superconductor Ferromagnetic Hybrids
Jacob CutshallReedA New Form of Quantum Tomography
Mina FasihiMinesComplex network description of phase transitions in the classical and quantum disordered Ising Model
Patrick HarringtonWash U.Photonic transport in quantum metamaterials
Joel HowardMinesInvestigating Entanglement Rates of Coupled Superconducting Qubits
Matthew JonesMinesOpen Source Matrix Product States: A Simulation Platform for Quantum Computing Technologies
Eric JonesMinesVariational preparation of quantum Hall states on a lattice
Sarah JonesMinesEffects of Nanoparticle Size and Density on Vortex Creep in (Y,Gd)BCO Films
Daria KowsariWash U.Memory in non-Markovian Open Quantum Systems
Suyesh KoyuUNRQuantum Coherent Dynamics from Thermal Noise: A Three-level V-system Driven by Incoherent Radiation
Alex LidiakMinesQuantum State Compression and Analysis via Dimensionality Reduction
Brad LloydMinesQuantum Dots in Silicon as a Candidate Platform for Scalable Quantum Computing and Quantum Neuromorphic Devices
Nick MateriseMinesQuantum Heat Engine Simulated on Superconducting Qubits
David Rodriguez PerezMinesVariable Dissipation in Small Logical Qubits
Zhijie TangMinesTheoretical survey of unconventional quantum annealing methods applied to a difficult trial problem
Brooks VenutiMinesProbing Magnetic Skyrmions in the Presence of Disorder
Joshua LewisMinesFractional Calculus in the Analysis of Quantum Systems

Attendees

NameInstitution
Adams, DanielColorado School of Mines
Alberi, KirstinNational Renewable Energy Laboratory
Alrumaih, AmaniColorado School of Mines
Bachman, KateColorado School of Mines
Bauers, SageNational Renewable Energy Laboratory
Beard, MattNational Renewable Energy Laboratory
Beck, MarkReed College
Becker, DylonColorado School of Mines
Been, JoelColorado School of Mines
Bielejec, EdwardSandia National Lab
Blagg, KirstenColorado School of Mines
Brennecka, GeoffColorado School of Mines
Breznay, NicholasHarvey Mudd College
Brooks, JeremyColorado School of Mines
Brown, KirstenColorado School of Mines
Bruce, KaneColorado School of Mines
Bush, BrianNational Renewable Energy Laboratory
Carr, LincolnColorado School of Mines
Chen, XiaowenNational Renewable Energy Laboratory
Chen, XihanNational Renewable Energy Laboratory
Cole, HaleyColorado School of Mines
Collins, ReubenColorado School of Mines
Cutshall, JacobReed College
DeMott, RoswellColorado School of Mines
DeWolf-Moura, TyjalColorado School of Mines
Downie, KhloeColorado School of Mines
Eley, SerenaColorado School of Mines
Fasihi, MinaColorado School of Mines
Fearing, StevenColorado School of Mines
Ferguson, AndrewNational Renewable Energy Laboratory
Giddins, HeatherColorado School of Mines
Godfrey, ChristianColorado School of Mines
Gong, ZhexuanColorado School of Mines
Gorman, BrianColorado School of Mines
Haack, CaseyColorado School of Mines
Halaoui, AdamThe University of Denver
Harrington, PatrickWashington University St. Louis
Honors, DylanColorado School of Mines
Howard, JoelColorado School of Mines
Hurst, HilaryJoint Quantum Institute/San Jose State University
Iverson, GabrielJoint Quantum Institute/San Jose State University
Jameson, CaseyColorado School of Mines
Johnson, JustinNational Renewable Energy Laboratory
Jones, EricColorado School of Mines
Jones, MatthewColorado School of Mines
Jones, SarahColorado School of Mines
Kapit, EliotColorado School of Mines
Kehyias, PauliSandia National Lab
Kelly, BrianColorado School of Mines
Khatami, EhsanSan Jose State University
Kowsari, DariaWashington University St. Louis
Koyu, SuyeshUniversity of Nevada Reno
Kuklin, JacksonColorado School of Mines
Kumar, NitinColorado School of Mines
Lewis, JoshColorado School of Mines
Lewis, RupertSandia National Lab
Lidiak, AlexanderColorado School of Mines
Lloyd, BradleyColorado School of Mines
Lu, Tzu-MingSandia National Lab
Luhman, DwightSandia National Lab
Lusk, MarkColorado School of Mines
Lynn, TheresaHarvey Mudd College
Materise, NickColorado School of Mines
Matlock, CharlesColorado School of Mines
McKinsey, JosephColorado School of Mines
McMullen, SkylerColorado School of Mines
McPherson, AlexandriaColorado School of Mines
McRae, Corey RaeNational Institute of Standards and Technology
Mi, XiaoGoogle
Mikulich, AlexanderColorado School of Mines
Mohammad, MajidColorado School of Mines
Monaghan, AustinColorado School of Mines
Moses, JoshuaColorado School of Mines
Murch, KaterWashington University St. Louis
Niyonkuru, PaulColorado School of Mines
Osella, AnnaNational Renewable Energy Laboratory
Parrott, ZacharyColorado School of Mines
Paver, BrendanColorado School of Mines
Quispe-Flores, CarlaColorado School of Mines
Ramos De Oliveira, JonaColorado School of Mines
Riddle, SamColorado School of Mines
Rodriguez Perez, DavidColorado School of Mines
Sanders, CalebColorado School of Mines
Scalettar, RichardUniversity of California Davis
Schenken, WilliamColorado School of Mines
Schroeter, DarrellReed College
Selinger, AlanColorado School of Mines
Simmonds, RayNational Institute of Standards and Technology
Singh, MeenakshiColorado School of Mines
Smith, ConnorColorado School of Mines
Soto Ramos de Oliveira, JonatanSoto Ramos de Oliveira
Stone, ChuckColorado School of Mines
Supple, EdwinColorado School of Mines
Swirtz, MadisonColorado School of Mines
Tang, ZhijeColorado School of Mines
Tavenner, JacobColorado School of Mines
Tellez Gonzalez, JaimeColorado School of Mines
Torres, AndrewUniversity of Denver
Tscherbul, TimurUniversity of Nevada Reno
Varosy, PaulColorado School of Mines
Venuti, BrooksColorado School of Mines
Wagner, TaylorColorado School of Mines
Walden, MichaelColorado School of Mines
Wiesner, LauraColorado School of Mines
Willner, JacksonColorado School of Mines
Wilson, AlexanderColorado School of Mines
Wu, DavidColorado School of Mines
Zabrocky, MalloryColorado School of Mines
Ziyad, JalanReed College

Lodging and Travel

Workshop lodging will be at Table Mountain Inn and can be arranged through us at quantum@mines.edu.

Plane tickets will be reimbursed for workshop participants coming from outside Colorado, and confirmed speakers or participants should go ahead and purchase those.  Please double check with us at quantum@mines.edu if your cost is over $400.

For getting to Golden, we recommend the easy and reliable lightrail system that leaves directly from the airport:
RTD rail system, Rail System Map
Take the A train from the airport to Union station at the end of the A line. Then transfer to the W train and ride it to the end of the W line in Golden. There is a small bus every 15 minutes that takes you straight downtown from there.

Uber and Lyft are about $60-80 one way. A taxi will cost around $100+. Other alternatives include:
Denvers Airport Transportation
Transit Van Shuttle

Introduction

We are pleased to invite you to the 1st Workshop of the Open Quantum Frontier Institute, which will take place at the Colorado School of Mines in Golden, CO on February 21-22, 2020. The purpose of the workshop is to advance quantum information research in noisy and open quantum systems and build quantum engineering education programs throughout the U.S. Our two-day workshop will feature:

  • Invited talks given by professors, postdocs, and senior researchers
  • Posters presented by postdocs, graduate, and undergraduate students
  • Poster award
  • Student travel support (TBD)
  • Catered lunch and coffee breaks

For more information, please contact quantum@mines.edu.

Registration Information

Our workshop is open for broad participation and can support up to 180 attendees.

Online registration closed on February 19, 2020. You may still be able to register. Please contact us at quantum@mines.edu.

Conference Location

Friday 2/21 and Saturday 2/22, Green Center Metals Hall, Colorado School of Mines

Schedule

Date, TimeActivity
Friday 2/21
08:00-09:00 AM Registration, Breakfast, Coffee
09:00-09:15 AMLincoln Carr Welcoming Remarks
Oral Session I
Quantum Simulations
Mina Fasihi, Chair
25 min talk, 5 minutes for questions
09:15-09:45 AMHilary Hurst, Joint Quantum Institute/San Jose State University

Quantum Control with Spinor Bose-Einstein Condensates

Understanding and controlling many-body quantum systems in noisy environments is paramount to developing robust quantum technologies. An external environment can be thought of as a measurement reservoir which extracts information about the quantum system. Cold atoms are well suited to examine system-environment interaction via weak (i.e. minimally destructive) measurement techniques, wherein the measurement probe acts as the environment and also provides a noisy record of system dynamics. The measurement record can then be used in a feedback scheme, opening the door to real time control of quantum gases. In this talk I discuss our theoretical proposal to use weak measurement and feedback to engineer new phases in spin-1/2 Bose-Einstein condensates. We show that measurement and feedback alters the effective Hamiltonian governing system dynamics, thereby driving phase transitions reminiscent of a quantum quench for the closed system. We also develop a feedback cooling protocol which prevents runaway heating of the condensate due to measurement backaction. Our results show that measurement and feedback can alter condensate dynamics in a stable, controllable manner and provides a route toward Hamiltonian engineering in many-body systems. Finally, I will discuss ongoing experimental work to realize our proposal using Rb87.

Speaker Bio: Hilary Hurst received her BS in Engineering Physics from the Colorado School of Mines. She went on to earn a Masters in Theoretical Physics at the University of Cambridge and received her PhD in physics from the University of Maryland. She is currently an NRC Postdoctoral Fellow at NIST and the Joint Quantum Institute and will be joining the faculty at San Jose State University in the Fall. Her areas of research include quantum measurement and feedback control for many-body systems and magnetization dynamics in dissipative systems.
09:45-10:15 AMRichard T. Scalettar, University of California Davis

Quantum Simulation Studies of Charge Patterns in Fermi-Bose Systems

The Holstein Model describes the interaction between fermions and a collection of local (dispersionless) phonon modes, and has intimate connections to the attractive Hubbard Hamiltonian. In the dilute limit, the phonon degrees of freedom dress the fermions, giving rise to polaron and bipolaron formation. At higher densities, the phonons mediate collective superconducting (SC) and charge density wave (CDW) phases. I will review the basic physics of the Holstein model and show results of some recent Quantum Monte Carlo (QMC) simulations where we have determined the quantum critical point and finite temperature transition points of the Holstein model on a honeycomb lattice, and also on the role of phonon dispersion on SC and CDW order. I will conclude the presentation by discussing a new, Langevin-based, algorithm which might allow connections to cold atom quantum simulators of Bose-Fermi mixtures.

Speaker Bio: Richard Scalettar received his PhD in physics in 1986 from the University of California, Santa Barbara. In 1989, after a post-doc in the Chemistry Department at the University of Illinois, Urbana-Champaign, he joined the Physics faculty at the University of California, Davis. Prof. Scalettar's research is in the application of Quantum Monte Carlo methods to problems in quantum magnetism, superconductivity, and localization. He was elected Fellow of the American Physical Society in 2004, and served as chair of the APS Division of Computational Physics in 2010. In 2009, he received the Chancellor's Outstanding Undergraduate Mentor Award at UC Davis, and in 2014 was named as an outstanding referee of the American Physical Society.
10:15-10:30 AM Coffee and Snacks
Oral Session II
Quantum Computing 1
Matthew Jones, Chair
10:30-11:00 AMZhexuan Gong, Colorado School of Mines

Speed limit of entangling gates in quantum computers: Theory and Experiment.

Fast two-qubit entangling gates are essential for quantum computers with finite coherence times. Due to the limit of interaction strength among qubits, there exists a theoretical speed limit for a given two-qubit entangling gate. This speed limit has been explicitly found only for a two-qubit system and under the assumption of negligible single qubit gate time. We propose to demonstrate such speed limit experimentally using two superconducting transmon qubits with an always-on capacitive coupling. Moreover, we investigate a modified speed limit when single qubit gate time is not negligible, as in any practical experimental setup. Finally, we study the generalization to multiple qubit systems where the coupling to additional qubits can significantly increase the speed limit of a two-qubit entangling gate, thus requiring the co-design of the quantum computer from both theorists and experimentalists for optimal gate performance.

Speaker Bio: Zhexuan Gong received his PhD in Physics from the University of Michigan in 2013. He was then a postdoctoral research associate and research scientist at the Joint Quantum Institute, University of Maryland and NIST. He joined Mines in 2018 as an assistant professor and also holds a NIST associate position. His areas of research include quantum computing, quantum information theory, and quantum many-body physics.
11:00-11:30 AMXiao Mi, Google

Quantum supremacy using a programmable superconducting processor

The promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here we report the use of a processor with programmable superconducting qubits to create quantum states on 53 qubits, corresponding to a computational state-space of dimension 253 (about 1016). Measurements from repeated experiments sample the resulting probability distribution, which we verify using classical simulations. Our Sycamore processor takes about 200 seconds to sample one instance of a quantum circuit a million times—our benchmarks currently indicate that the equivalent task for a state-of-the-art classical supercomputer would take approximately 10,000 years. This dramatic increase in speed compared to all known classical algorithms is an experimental realization of quantum supremacy for this specific computational task, heralding a much-anticipated computing paradigm.

Speaker Bio: Xiao is an experimental physicst at Google working on quantum gate metrology and applications of near-term quantum processors to condensed matter physics problems. Prior to joing Google, Xiao pioneered the integration of circuit quantum electrodynamics with semiconductor spin qubits during his PhD at Princeton. He is the recipient of the 2020 Richard Greene Condensed Matter Thesis Prize from the American Physical Society.
Oral Session III
Open Quantum Systems
Tyjal Dewolf-Moura, Chair
11:30-12:00 PMEliot Kapit, Colorado School of Mines

Noise-tolerant quantum speedups in quantum annealing without fine tuning

Quantum annealing is a powerful alternative model for quantum computing, which can succeed in the presence of environmental noise even without error correction. However, despite great effort, no conclusive proof of a quantum speedup (relative to state of the art classical algorithms) has been shown for these systems, and rigorous theoretical proofs of a quantum advantage generally rely on exponential precision in at least some aspects of the system, an unphysical resource guaranteed to be scrambled by random noise. In this work, we propose a new variant of quantum annealing, called RFQA, which can maintain a scalable quantum speedup in the face of noise and modest control precision. Specifically, we consider a modification of flux qubit-based quantum annealing which includes random, but coherent, low-frequency oscillations in the directions of the transverse field terms as the system evolves. We show that this method produces a quantum speedup for finding ground states in the Grover problem and quantum random energy model, and thus should be widely applicable to other hard optimization problems which can be formulated as quantum spin glasses. Further, we show that this speedup should be resilient to two realistic noise channels (1⁄f-like local potential fluctuations and local heating from interaction with a finite temperature bath), and that another noise channel, bath-assisted quantum phase transitions, actually accelerates the algorithm and may outweigh the negative effects of the others. The modifications we consider have a straightforward experimental implementation and could be explored with current technology.

Speaker Bio: Eliot Kapit receieved his PhD from Cornell in 2012. From there, he did postdocs at Oxford and the City University of New York, before starting as an Assistant Professor of Physics at Tulane University from 2015-2018. In summer 2018, he joined the faculty of Colorado School of Mines. His research focuses on quantum information, many-body physics, and novel superconducting circuits.
12:00-12:30 PMTimur Tscherbul, University of Nevada Reno

Quantum coherence from thermal noise: From coherent dynamics to non-equilibrium steady states

Quantum coherence is widely regarded as an essential resource for quantum information processing and quantum sensing. In this talk, I will present an overview of our recent work on the quantum dynamics of noise-induced Fano coherences that occur in multilevel quantum systems interacting with a thermal bath (such as blackbody radiation) in the absence of coherent driving. By solving the nonsecular Bloch-Redfield quantum master equation for a model three-level V-system driven by a thermal bath, we show that Fano coherences exhibit quantum beats when the spacing between the excited states of the V-system is large compared to the radiative decay rates. In the opposite limit of small excited-state spacing, we observe the emergence of non-equilibrium quasi-steady states, which become true non-equilibrium steady states if the thermal driving is polarized. The general theory will be illustrated with two examples involving the time evolution of Fano coherences in Rydberg atoms immersed in blackbody radiation and the breaking of detailed balance in atomic calcium driven by polarized incoherent light. Implications of these results for quantum information processing and quantum thermodynamics will be discussed.

Speaker Bio: Tscherbul Timur earned his PhD from Moscow State University, and received a Killam postdoctoral fellowship at the University of British Columbia. He joined the faculty at the University of Nevada, Reno in 2015 after working as a postdoc at Harvard and the University of Toronto. He is a computational quantum physisist interested in the theory of open quantum systems, quantum dynamics and control of complex atomic and molecular systems, quantum impurity problems, and diagrammatic Monte Carlo methods.
12:30-01:30 PM Catered Lunch
Oral Session IV
Quantum Computing 2
Kirsten Blagg, Chair
01:30-02:00 PMJustin Johnson, National Renewable Energy Lab

Molecular approaches to robust qubits: theory, structures, and spectroscopy

The versatility of chemical substitution provides nearly infinite space for controlling energy levels and electronic/spin population flow in conjugated organic molecules, and as such, excited-state molecular systems may lend themselves robust qubits with unique properties. We have chosen to investigate the spin states of triplet exciton pairs that are generated quickly upon photoexcitation of tailored molecules and appear to be protected from decoherence even at room temperature until decay to the ground state on a microsecond timescale. Strong spin polarization seems inherent in some of these systems, as detected through the distinct pattern of microwave absorption in a static magnetic field (i.e., EPR spectra). Furthermore, some molecules produce photon emission that is dependent on the exact spin state, much like nitrogen vacancy in diamond systems where magnetic resonance is detected optically. We are a building a library of molecules that can be coupled to each other with tunable strengths and geometries in order to understand the fundamental properties of spin-entangled triplet pairs, and more incisively to evaluate whether or not there might be inherent advantages of this approach, especially in terms of sensitivity to noise, compared with more conventional open quantum systems. This is an early stage and focused effort, but we hope to make connections to other work to uncover synergies or extensions of our ideas and capabilities that impact QIS more broadly.

Speaker Bio: Justin Johnson has been a senior scientist at the National Renewable Energy Laboratory (NREL) since 2008 and is also a joint appointee in Chemistry at Colorado School of Mines. He received his Ph.D. in Chemistry from the University of California, Berkeley, in 2004 and subsequently did postdoctoral work with Dr. Arthur Nozik at NREL and Prof. Josef Michl at the University of Colorado, Boulder. His technical expertise is in ultrafast and nonlinear spectroscopy, and his research interests include investigating the dynamics of photophysical phenomena associated with solar light harvesting, energy storage, and quantum information in both molecular and nanoscale semiconductor systems.
02:00-02:30 PMRaymond Simmonds, National Institute of Standards and Technology

Manipulating mechanical and electrical quanta with parametric circuits

Parametric processes are ubiquitous in nature. At their heart is an interaction that involves a nonlinear relationship between changing quantities. These processes can lead to energy transport in different forms. One form produces amplification, like the well -known example of a child on a swing who periodically changes her center of gravity causing the resonance frequency of the swing to be modulated, inducing more swinging. Here, energy from her pumping legs at one frequency is absorbed and transferred into more motion at a different swinging frequency. This type of phenomenon can be mechanical (as with a swing) or electrical in nature, lending itself to many useful technological applications. Parametric processes are paramount for new emerging quantum information technologies like laser-cooled trapped ions, linear quantum optics, or opto-mechanics. Analogous physical systems can be created on a single chip using superconducting circuits, along with nonlinear Josephson junctions, or metalized flexible membrane capacitors. In this talk, I will discuss our experimental efforts at NIST to utilize parametric interactions to help control different physical processes that are important manipulating quantum information. Harnessing these processes on-chip with superconducting circuit components, including micro-drum mechanical resonators, electromagnetic cavity modes, and superconducting quantum bits provides a highly programmable platform for engineering both closed and open quantum systems for simulation or computation.

Speaker Bio: Ray Simmonds received his BA, MA, and PhD from the University of California, Berkeley in 2002, where he studied Quantum Interfrence in superfluid He-3. After a 2 year post-doc at NIST in Boulder CO developing superconducting quantum bits, he became a staff physicist. His current research is focused on the application of superconducting microwave and optomechanical circuit techniques for quantum information, measurement, and computing.
02:30-03:00 PM Coffee and Cookies
03:00-06:00 PMOpen Quantum Frontier Institute Strategy Meeting and Breakout Sessions
Saturday 2/22
08:00-09:00 AMBreakfast, Coffee
08:50 AM Opening Remarks
Oral Session V
Materials for Quantum Information Science
Edwin Supple, Chair
09:00-09:30 AMTzu-Ming Lu, Sandia National Lab

Hole spins in Ge/GeSi heterostructures

There is growing interest in leveraging the unique properties of hole-carrier systems and their intrinsically strong spin-orbit coupling to engineer novel qubits. For example, qubit controls using electric dipole spin resonance have recently been demonstrated in Ge/GeSi hole quantum dots. In this talk, we will present unique physical properties of holes in Ge/GeSi heterostructures as well as our ongoing efforts toward hole spin qubits, including development of gated device architectures, charge sensing, and magneto-spectroscopy in the few-hole regime. We will also present our theoretical understanding and modeling of electric dipole spin resonance of holes in Ge quantum dots through intrinsic spin-orbit coupling. An effective two-level Hamiltonian for the spin of an individual hole is derived from the strain of the heterostructure and electrostatic potential, allowing for predictions on how the spin will respond to applied AC fields. Acknowledgements: This work was funded, in part, by the Laboratory Directed Research and Development Program and performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the US Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in this article do not necessarily represent the views of the US Department of Energy or the United States Government. The work at NTU was supported by the Ministry of Science and Technology (107-2622-8-002-018-).

Speaker Bio: Tzu-Ming Lu received his B.S. from National Taiwan University in 2004 and Ph.D. from Princeton University in 2011. After graduate school, he was a postdoctoral researcher at Sandia National Laboratories, New Mexico, where he is currently a Senior Member of Technical Staff. His research topics include semiconductor device physics, spin-orbit coupling in solid-state systems, and quantum behavior of nanoscale structures. He is also a Center for Integrated Nanotechnologies (CINT) scientist, supporting user projects on quantum information science and solid-state physics at the nanoscale.
09:30-10:00 AMRupert Lewis, Sandia National Lab

Reversible Superconducting Logic for Low Power Computation

Reversible computing is the ultimate low energy computing technology. To be reversible, a computational operation must not only be able to run forward or backward but must preserve the energy of a bit. In practice, performing logic operations at or below the Landauer limit of kBT ln2 per logical operation is the goal of the field. Superconducting circuits are the perfect technology for implementing ballistic reversible circuits due to inherently low losses and the use of single flux quanta as robust bits. I will discuss our progress towards an asynchronous ballistic reversible logic based on fluxons propagating along superconducting lines and incorporating Josephson junctions as active elements. While superconducting logic families have the long-term potential of transforming high performance computing such as data centers, in the near term, the greatest impact is likely to be on quantum computers where the low energy dissipation (relative to transistorized logic) will enable in cryostat control of quantum computers. Funding Statement: Supported by the LDRD program at SNL, a multi-mission laboratory managed and operated by NTESS, LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. DOE’s NNSA under contract DE-NA0003525.

Speaker Bio: Rupert Lewis received his PhD from Indiana University in 2001. He completed post-docs at the National High Magnetic Field Lab (in Tallahassee) and at the the University of Maryland where he worked on such diverse subjects as Wigner crystalization of 2D electron systems and superconducting implementations of quantum computing. Recently, he's branched out into reversible computing. He's been a staff member at Sandia since 2013.
10:00-10:30 AM Corey Rae McRea, National Institute of Standards and Technology

The Boulder Cryogenic Quantum Testbed

The investigation of materials losses at low powers and temperatures has been identified as critical for increasing performance and scalability of superconducting quantum computers. This investigation requires the dissemination of a community standard for the accurate and repeatable measurement and analysis of superconducting microwave resonators. JILA / CU’s Boulder Cryogenic Quantum Testbed (CQT) is a non-profit, pre-competitive research facility for developing and openly disseminating standard protocols to reproducibly measure the quality factor and performance characteristics of superconducting microwave resonators used in quantum computing circuits. The testbed was founded on a philosophy of open collaborative science by a joint initiative between government, academic, and industry partners.

Speaker Bio: Corey Rae McRae received her PhD in Quantum Information from the University of Waterloo in 2018. She is now a postdoctoral researcher at the National Institute of Standards and Technology Boulder, as well as the director of the Boulder Cryogenic Quantum Testbed at JILA, University of Colorado Boulder. She studies materials losses in superconducting quantum circuits as well as the behavior and performance of superconducting microwave resonators.
10:30-11:00 AMCoffee and Snacks
Oral Session VI
Quantum Measurement and Sensing
Joel Howard, Chair
11:00-11:30 AMKater Murch, Washington University

Superconducting quantum circuits: exploring frontiers of quantum measurement and dissipation at microwave frequencies

Josephson junction based quantum circuits have enabled broad exploration into open quantum systems in the microwave frequency domain. The combination of coherent quantum bits, robust single qubit control, and quantum noise limited parametric amplifiers has yielded an unprecedented view into the physics of quantum measurement and quantum dissipation. I will survey a range of research topics that are currently open to experimental exploration with this platform, including weak measurement and quantum trajectories, non-Markovian dynamics, effective non-Hermitian dynamics, quantum thermodynamics, and quantum sensing.

Speaker Bio: Kater Murch received his PhD in physics in 2008 from the University of California, Berkeley, with disseration research focusing on cold atom cavity QED and measurement backaction. His postdoctoral work at UC Berkeley focused on superconducting quantum circuits and quantum measurement. Since 2014, he has been at Washington University in St. Louis with work focusing on open quantum systems experiment with superconducting circuits. Kater has received an Alfred P. Sloan fellowship, an NSF CAREER award, and a Cottrell Scholar award.
11:30-12:00 PMPauli Kehayias, Sandia National Lab

Magnetic sensing using nitrogen-vacancy centers in diamond

Nitrogen-vacancy (NV) centers in diamond have gained much recent interest for their uses in magnetic sensing and quantum information. NV centers are fluorescent defect centers that have discrete electronic states with few-millisecond lifetimes, can be optically initialized and read out, are magnetically sensitive, and work in ambient conditions or extreme environments. Furthermore, our ability to place NV centers near the diamond surface (as close as a few nanometers) enables us to have a small separation between the NVs and external magnetic field sources, allowing us to sense external sources with high spatial resolution and sensitivity. After introducing NV DC and AC magnetometry techniques, I will present some ongoing NV magnetic sensing applications, including small-volume NMR spectroscopy, magnetometry and pressure sensing in a diamond anvil cell, and magnetic microscopy for geology, biology, and condensed-matter physics.

Speaker Bio: Pauli did his PhD work at UC Berkeley, after which he was a postdoc at Harvard. Currently he is a Truman Fellowship postdoc at Sandia National Labs. He works on magnetic sensing and imaging with nitrogen-vacancy centers in diamond, with applications in NMR spectroscopy, paleomagnetism, biomagnetism, and magnetic materials.
12:00-01:00 PM Catered Lunch and Breakout Session
Oral Session VII
Quantum Education
Casey Jameson, Chair
25 min talk, 5 minutes for questions
01:00-01:30 PMMark Beck, Reed College

Exploring Fundamentals of Quantum Mechanics with Optics

Individual photons and entangled-photon pairs are excellent resources for exploring fundamental questions in quantum mechanics. We, and others, have developed a number of teaching laboratories that use these resources to do precisely that. The experiments include: "Proving" that light consists of photons, single-photon interference, and tests of local realism. I will describe some of these experiments, as well as the physics behind them. I will also describe our recent work on experiments that involve more than two photons.

Speaker Bio: Mark Beck received his BS and PhD degrees in Optics from the University of Rochester. He was a postdoctoral researcher at the University of Oregon, and has taught physics at Reed College and Whitman College since 1994. His areas of research specialization are quantum optics and quantum measurement. In 2018 he was the recipient of the Richtmyer Memorial Lecture Award from the American Association of Physics Teachers.
01:30-02:00 PMTheresa Lynn, Harvey Mudd College

Quantum Secrets: Protecting Them in the Laboratory, Unraveling Them in the Classroom

I report on aspects of quantum education at Harvey Mudd beyond the quantum mechanics course sequence for physics majors. In upper-level physics labs, for example, entangled photon experiments allow direct experimental investigation of phenomena central to quantum information, while NMR experiments give students valuable exposure to working with pulse sequences and the language of coherence times. In introductory courses, principles of quantum mechanics have been presented in the contexts of quantum optics and of materials science at both the first-semester and sophomore levels. And outside the major, our undergraduate quantum information course relies on linear algebra but minimal background in physics, and regularly enrolls the majority of its students from outside the physics major (chiefly computer science and math majors). Time permitting, I will supplement this overview of quantum education at Harvey Mudd with some recent undergraduate research in my quantum optics group, where our work focuses on non-ideal situations involving entanglement. In one project, we measure photon pairs partially entangled in polarization to show that certain partially entangled states have a surprising one-way feature in the way that measurements on one particle non-classically alter the measurement statistics of the second (EPR steering). In another project, we have established several limits on how well non-entangling measurements can perform generalized Bell measurements on entangled states more complex than the two-qubit case; these limits are relevant to recent and near-term experimental realizations of quantum teleportation and dense coding protocols.

Speaker Bio: Theresa Lynn received her B.A. in physics from Harvard and did her Ph.D. at Caltech doing experimental quantum optics and atomic physics. After working as a postdoc and staff scientist at Caltech in educational outreach and nuclear astrophysics, Theresa returned to AMO physics when she took a faculty position at Harvey Mudd College, where she has been since 2006. Her current research areas are quantum optics and fundamentals of quantum mechanics. Since 2014 she has taught an introductory quantum information course to an audience of physics and other STEM majors.
02:00-04:00 PM

Poster Session with Coffee and Cookies

Kirsten Blagg
Colorado School of Mines
Thermoelectric Effects in Superconductor Ferromagnetic Hybrids

Jacob Cutshall
Reed College
A New Form of Quantum Tomography

Mina Fasihi
Colorado School of Mines
Complex Network Description of Phase Transitions in the Classical and Quantum Disordered Ising Model

Patrick Harrington
Washington University St. Louis
Photonic Transport in Quantum Metamaterials

Joel Howard
Colorado School of Mines
Investigating Entanglement Rates of Coupled Superconducting Qubits

Eric Jones
Colorado School of Mines
Variational Preparation of Quantum Hall States on a Lattice

Matthew Jones
Colorado School of Mines
Open Source Matrix Product States: A Simulation Platform for Quantum Computing Technologies

Daria Kowsari
Washington University St. Louis
Memory in Non-Markovian Open Quantum Systems

Suyesh Koyu
University of Nevada Reno
Quantum Coherent Dynamics from Thermal Noise: A Three-level V-system Driven by Incoherent Radiation

Joshua Lewis
Colorado School of Mines
Use of Fractional Calculus in the Analysis of Quantum Systems

Alex Lidiak
Colorado School of Mines
Quantum State Compression and Analysis via Dimensionality Reduction

Bradley Lloyd
Colorado School of Mines
Quantum Dots in Silicon as a Candidate Platform for Scalable Quantum Computing and Quantum Neuromorphic Devices

Nick Materise
Colorado School of Mines
Quantum Heat Engine Simulated on Superconducting Qubits

David Rodriguez Perez
Colorado School of Mines
Variable Dissipation in Small Logical Qubits

Zhijie Tang
Colorado School of Mines
Theoretical Survey of Unconventional Quantum Annealing Methods Applied to a Difficult Trial Problem

Brooks Venuti
Colorado School of Mines
Probing Magnetic Skyrmions in the Presence of Disorder
04:00-04:30 PM Poster Awards, Final Remarks. Workshop ends for most participants
04:30-05:00 PM Breakout Session Summaries: Recommendations for QLCI Proposal
05:00-06:00 PM Open Quantum Frontier Institute Strategy Closed Meeting

Invited Speakers

Speaker/Inst/Abstract/Bio
Mark Beck, Reed College

Exploring Fundamentals of Quantum Mechanics with Optics

Individual photons and entangled-photon pairs are excellent resources for exploring fundamental questions in quantum mechanics. We, and others, have developed a number of teaching laboratories that use these resources to do precisely that. The experiments include: "Proving" that light consists of photons, single-photon interference, and tests of local realism. I will describe some of these experiments, as well as the physics behind them. I will also describe our recent work on experiments that involve more than two photons.

Speaker Bio: Mark Beck received his BS and PhD degrees in Optics from the University of Rochester. He was a postdoctoral researcher at the University of Oregon, and has taught physics at Reed College and Whitman College since 1994. His areas of research specialization are quantum optics and quantum measurement. In 2018 he was the recipient of the Richtmyer Memorial Lecture Award from the American Association of Physics Teachers.
Hilary Hurst, Joint Quantum Institute/San Jose State University

Quantum Control with Spinor Bose-Einstein Condensates

Quantum Control with Spinor Bose-Einstein Condensates

Understanding and controlling many-body quantum systems in noisy environments is paramount to developing robust quantum technologies. An external environment can be thought of as a measurement reservoir which extracts information about the quantum system. Cold atoms are well suited to examine system-environment interaction via weak (i.e. minimally destructive) measurement techniques, wherein the measurement probe acts as the environment and also provides a noisy record of system dynamics. The measurement record can then be used in a feedback scheme, opening the door to real time control of quantum gases. In this talk I discuss our theoretical proposal to use weak measurement and feedback to engineer new phases in spin-1/2 Bose-Einstein condensates. We show that measurement and feedback alters the effective Hamiltonian governing system dynamics, thereby driving phase transitions reminiscent of a quantum quench for the closed system. We also develop a feedback cooling protocol which prevents runaway heating of the condensate due to measurement backaction. Our results show that measurement and feedback can alter condensate dynamics in a stable, controllable manner and provides a route toward Hamiltonian engineering in many-body systems. Finally, I will discuss ongoing experimental work to realize our proposal using Rb87.

Speaker Bio: Hilary Hurst received her BS in Engineering Physics from the Colorado School of Mines. She went on to earn a Masters in Theoretical Physics at the University of Cambridge and received her PhD in physics from the University of Maryland. She is currently an NRC Postdoctoral Fellow at NIST and the Joint Quantum Institute and will be joining the faculty at San Jose State University in the Fall. Her areas of research include quantum measurement and feedback control for many-body systems and magnetization dynamics in dissipative systems.
Justin Johnson, National Renewable Energy Lab

Molecular approaches to robust qubits: theory, structures, and spectroscopy

The versatility of chemical substitution provides nearly infinite space for controlling energy levels and electronic/spin population flow in conjugated organic molecules, and as such, excited-state molecular systems may lend themselves robust qubits with unique properties. We have chosen to investigate the spin states of triplet exciton pairs that are generated quickly upon photoexcitation of tailored molecules and appear to be protected from decoherence even at room temperature until decay to the ground state on a microsecond timescale. Strong spin polarization seems inherent in some of these systems, as detected through the distinct pattern of microwave absorption in a static magnetic field (i.e., EPR spectra). Furthermore, some molecules produce photon emission that is dependent on the exact spin state, much like nitrogen vacancy in diamond systems where magnetic resonance is detected optically. We are a building a library of molecules that can be coupled to each other with tunable strengths and geometries in order to understand the fundamental properties of spin-entangled triplet pairs, and more incisively to evaluate whether or not there might be inherent advantages of this approach, especially in terms of sensitivity to noise, compared with more conventional open quantum systems. This is an early stage and focused effort, but we hope to make connections to other work to uncover synergies or extensions of our ideas and capabilities that impact QIS more broadly.

Speaker Bio: Justin Johnson has been a senior scientist at the National Renewable Energy Laboratory (NREL) since 2008 and is also a joint appointee in Chemistry at Colorado School of Mines. He received his Ph.D. in Chemistry from the University of California, Berkeley, in 2004 and subsequently did postdoctoral work with Dr. Arthur Nozik at NREL and Prof. Josef Michl at the University of Colorado, Boulder. His technical expertise is in ultrafast and nonlinear spectroscopy, and his research interests include investigating the dynamics of photophysical phenomena associated with solar light harvesting, energy storage, and quantum information in both molecular and nanoscale semiconductor systems.
Eliot Kapit, Colorado School of Mines

Noise-tolerant quantum speedups in quantum annealing without fine tuning

Quantum annealing is a powerful alternative model for quantum computing, which can succeed in the presence of environmental noise even without error correction. However, despite great effort, no conclusive proof of a quantum speedup (relative to state of the art classical algorithms) has been shown for these systems, and rigorous theoretical proofs of a quantum advantage generally rely on exponential precision in at least some aspects of the system, an unphysical resource guaranteed to be scrambled by random noise. In this work, we propose a new variant of quantum annealing, called RFQA, which can maintain a scalable quantum speedup in the face of noise and modest control precision. Specifically, we consider a modification of flux qubit-based quantum annealing which includes random, but coherent, low-frequency oscillations in the directions of the transverse field terms as the system evolves. We show that this method produces a quantum speedup for finding ground states in the Grover problem and quantum random energy model, and thus should be widely applicable to other hard optimization problems which can be formulated as quantum spin glasses. Further, we show that this speedup should be resilient to two realistic noise channels (1⁄f-like local potential fluctuations and local heating from interaction with a finite temperature bath), and that another noise channel, bath-assisted quantum phase transitions, actually accelerates the algorithm and may outweigh the negative effects of the others. The modifications we consider have a straightforward experimental implementation and could be explored with current technology.

Speaker Bio: Eliot Kapit receieved his PhD from Cornell in 2012. From there, he did postdocs at Oxford and the City University of New York, before starting as an Assistant Professor of Physics at Tulane University from 2015-2018. In summer 2018, he joined the faculty of Colorado School of Mines. His research focuses on quantum information, many-body physics, and novel superconducting circuits.
Pauli Kehayias, Sandia National Lab

Magnetic sensing using nitrogen-vacancy centers in diamond

Nitrogen-vacancy (NV) centers in diamond have gained much recent interest for their uses in magnetic sensing and quantum information. NV centers are fluorescent defect centers that have discrete electronic states with few-millisecond lifetimes, can be optically initialized and read out, are magnetically sensitive, and work in ambient conditions or extreme environments. Furthermore, our ability to place NV centers near the diamond surface (as close as a few nanometers) enables us to have a small separation between the NVs and external magnetic field sources, allowing us to sense external sources with high spatial resolution and sensitivity. After introducing NV DC and AC magnetometry techniques, I will present some ongoing NV magnetic sensing applications, including small-volume NMR spectroscopy, magnetometry and pressure sensing in a diamond anvil cell, and magnetic microscopy for geology, biology, and condensed-matter physics.

Speaker Bio: Pauli did his PhD work at UC Berkeley, after which he was a postdoc at Harvard. Currently he is a Truman Fellowship postdoc at Sandia National Labs. He works on magnetic sensing and imaging with nitrogen-vacancy centers in diamond, with applications in NMR spectroscopy, paleomagnetism, biomagnetism, and magnetic materials.
Rupert Lewis, Sandia National Lab

Reversible Superconducting Logic for Low Power Computation

Reversible computing is the ultimate low energy computing technology. To be reversible, a computational operation must not only be able to run forward or backward but must preserve the energy of a bit. In practice, performing logic operations at or below the Landauer limit of kBT ln2 per logical operation is the goal of the field. Superconducting circuits are the perfect technology for implementing ballistic reversible circuits due to inherently low losses and the use of single flux quanta as robust bits. I will discuss our progress towards an asynchronous ballistic reversible logic based on fluxons propagating along superconducting lines and incorporating Josephson junctions as active elements. While superconducting logic families have the long-term potential of transforming high performance computing such as data centers, in the near term, the greatest impact is likely to be on quantum computers where the low energy dissipation (relative to transistorized logic) will enable in cryostat control of quantum computers. Funding Statement: Supported by the LDRD program at SNL, a multi-mission laboratory managed and operated by NTESS, LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. DOE’s NNSA under contract DE-NA0003525.

Speaker Bio: Rupert Lewis received his PhD from Indiana University in 2001. He completed post-docs at the National High Magnetic Field Lab (in Tallahassee) and at the the University of Maryland where he worked on such diverse subjects as Wigner crystalization of 2D electron systems and superconducting implementations of quantum computing. Recently, he's branched out into reversible computing. He's been a staff member at Sandia since 2013.
Tzu-Ming Lu, Sandia National Lab

Hole spins in Ge/GeSi heterostructures

There is growing interest in leveraging the unique properties of hole-carrier systems and their intrinsically strong spin-orbit coupling to engineer novel qubits. For example, qubit controls using electric dipole spin resonance have recently been demonstrated in Ge/GeSi hole quantum dots. In this talk, we will present unique physical properties of holes in Ge/GeSi heterostructures as well as our ongoing efforts toward hole spin qubits, including development of gated device architectures, charge sensing, and magneto-spectroscopy in the few-hole regime. We will also present our theoretical understanding and modeling of electric dipole spin resonance of holes in Ge quantum dots through intrinsic spin-orbit coupling. An effective two-level Hamiltonian for the spin of an individual hole is derived from the strain of the heterostructure and electrostatic potential, allowing for predictions on how the spin will respond to applied AC fields. Acknowledgements: This work was funded, in part, by the Laboratory Directed Research and Development Program and performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the US Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in this article do not necessarily represent the views of the US Department of Energy or the United States Government. The work at NTU was supported by the Ministry of Science and Technology (107-2622-8-002-018-).

Speaker Bio: Tzu-Ming Lu received his B.S. from National Taiwan University in 2004 and Ph.D. from Princeton University in 2011. After graduate school, he was a postdoctoral researcher at Sandia National Laboratories, New Mexico, where he is currently a Senior Member of Technical Staff. His research topics include semiconductor device physics, spin-orbit coupling in solid-state systems, and quantum behavior of nanoscale structures. He is also a Center for Integrated Nanotechnologies (CINT) scientist, supporting user projects on quantum information science and solid-state physics at the nanoscale.
Theresa Lynn, Harvey Mudd College

Quantum Secrets: Protecting Them in the Laboratory, Unraveling Them in the Classroom

I report on aspects of quantum education at Harvey Mudd beyond the quantum mechanics course sequence for physics majors. In upper-level physics labs, for example, entangled photon experiments allow direct experimental investigation of phenomena central to quantum information, while NMR experiments give students valuable exposure to working with pulse sequences and the language of coherence times. In introductory courses, principles of quantum mechanics have been presented in the contexts of quantum optics and of materials science at both the first-semester and sophomore levels. And outside the major, our undergraduate quantum information course relies on linear algebra but minimal background in physics, and regularly enrolls the majority of its students from outside the physics major (chiefly computer science and math majors). Time permitting, I will supplement this overview of quantum education at Harvey Mudd with some recent undergraduate research in my quantum optics group, where our work focuses on non-ideal situations involving entanglement. In one project, we measure photon pairs partially entangled in polarization to show that certain partially entangled states have a surprising one-way feature in the way that measurements on one particle non-classically alter the measurement statistics of the second (EPR steering). In another project, we have established several limits on how well non-entangling measurements can perform generalized Bell measurements on entangled states more complex than the two-qubit case; these limits are relevant to recent and near-term experimental realizations of quantum teleportation and dense coding protocols.

Speaker Bio: Theresa Lynn received her B.A. in physics from Harvard and did her Ph.D. at Caltech doing experimental quantum optics and atomic physics. After working as a postdoc and staff scientist at Caltech in educational outreach and nuclear astrophysics, Theresa returned to AMO physics when she took a faculty position at Harvey Mudd College, where she has been since 2006. Her current research areas are quantum optics and fundamentals of quantum mechanics. Since 2014 she has taught an introductory quantum information course to an audience of physics and other STEM majors.
Corey Rae McRea, National Institute of Standards and Technology

The Boulder Cryogenic Quantum Testbed

The investigation of materials losses at low powers and temperatures has been identified as critical for increasing performance and scalability of superconducting quantum computers. This investigation requires the dissemination of a community standard for the accurate and repeatable measurement and analysis of superconducting microwave resonators. JILA / CU’s Boulder Cryogenic Quantum Testbed (CQT) is a non-profit, pre-competitive research facility for developing and openly disseminating standard protocols to reproducibly measure the quality factor and performance characteristics of superconducting microwave resonators used in quantum computing circuits. The testbed was founded on a philosophy of open collaborative science by a joint initiative between government, academic, and industry partners.

Speaker Bio: Corey Rae McRae received her PhD in Quantum Information from the University of Waterloo in 2018. She is now a postdoctoral researcher at the National Institute of Standards and Technology Boulder, as well as the director of the Boulder Cryogenic Quantum Testbed at JILA, University of Colorado Boulder. She studies materials losses in superconducting quantum circuits as well as the behavior and performance of superconducting microwave resonators.
Xiao Mi, Google

Quantum supremacy using a programmable superconducting processor

The promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here we report the use of a processor with programmable superconducting qubits to create quantum states on 53 qubits, corresponding to a computational state-space of dimension 253 (about 1016). Measurements from repeated experiments sample the resulting probability distribution, which we verify using classical simulations. Our Sycamore processor takes about 200 seconds to sample one instance of a quantum circuit a million times—our benchmarks currently indicate that the equivalent task for a state-of-the-art classical supercomputer would take approximately 10,000 years. This dramatic increase in speed compared to all known classical algorithms is an experimental realization of quantum supremacy for this specific computational task, heralding a much-anticipated computing paradigm.

Speaker Bio: Xiao Mi is an experimental physicst at Google working on quantum gate metrology and applications of near-term quantum processors to condensed matter physics problems. Prior to joing Google, Xiao pioneered the integration of circuit quantum electrodynamics with semiconductor spin qubits during his PhD at Princeton. He is the recipient of the 2020 Richard Greene Condensed Matter Thesis Prize from the American Physical Society.
Kater Murch, Washington University

Superconducting quantum circuits: exploring frontiers of quantum measurement and dissipation at microwave frequencies

Superconducting quantum circuits: exploring frontiers of quantum measurement and dissipation at microwave frequencies

The combination of coherent quantum bits, robust single qubit control, and quantum noise limited parametric amplifiers has yielded an unprecedented view into the physics of quantum measurement and quantum dissipation. I will survey a range of research topics that are currently open to experimental exploration with this platform, including weak measurement and quantum trajectories, non-Markovian dynamics, effective non-Hermitian dynamics, quantum thermodynamics, and quantum sensing.

Speaker Bio: Kater Murch received his PhD in physics in 2008 from the University of California, Berkeley, with disseration research focusing on cold atom cavity QED and measurement backaction. His postdoctoral work at UC Berkeley focused on superconducting quantum circuits and quantum measurement. Since 2014, he has been at Washington University in St. Louis with work focusing on open quantum systems experiment with superconducting circuits. Kater has received an Alfred P. Sloan fellowship, an NSF CAREER award, and a Cottrell Scholar award.
Richard T. Scalettar, University of California Davis

Quantum Simulation Studies of Charge Patterns in Fermi-Bose Systems

Quantum Simulation Studies of Charge Patterns in Fermi-Bose Systems

The Holstein Model describes the interaction between fermions and a collection of local (dispersionless) phonon modes, and has intimate connections to the attractive Hubbard Hamiltonian. In the dilute limit, the phonon degrees of freedom dress the fermions, giving rise to polaron and bipolaron formation. At higher densities, the phonons mediate collective superconducting (SC) and charge density wave (CDW) phases. I will review the basic physics of the Holstein model and show results of some recent Quantum Monte Carlo (QMC) simulations where we have determined the quantum critical point and finite temperature transition points of the Holstein model on a honeycomb lattice, and also on the role of phonon dispersion on SC and CDW order. I will conclude the presentation by discussing a new, Langevin-based, algorithm which might allow connections to cold atom quantum simulators of Bose-Fermi mixtures.

Speaker Bio: Richard Scalettar received his PhD in physics in 1986 from the University of California, Santa Barbara. In 1989, after a post-doc in the Chemistry Department at the University of Illinois, Urbana-Champaign, he joined the Physics faculty at the University of California, Davis. Prof. Scalettar's research is in the application of Quantum Monte Carlo methods to problems in quantum magnetism, superconductivity, and localization. He was elected Fellow of the American Physical Society in 2004, and served as chair of the APS Division of Computational Physics in 2010. In 2009, he received the Chancellor's Outstanding Undergraduate Mentor Award at UC Davis, and in 2014 was named as an outstanding referee of the American Physical Society.
Raymond Simmonds, National Institute of Standards and Technology

Manipulating mechanical and electrical quanta with parametric circuits

Parametric processes are ubiquitous in nature. At their heart is an interaction that involves a nonlinear relationship between changing quantities. These processes can lead to energy transport in different forms. One form produces amplification, like the well -known example of a child on a swing who periodically changes her center of gravity causing the resonance frequency of the swing to be modulated, inducing more swinging. Here, energy from her pumping legs at one frequency is absorbed and transferred into more motion at a different swinging frequency. This type of phenomenon can be mechanical (as with a swing) or electrical in nature, lending itself to many useful technological applications. Parametric processes are paramount for new emerging quantum information technologies like laser-cooled trapped ions, linear quantum optics, or opto-mechanics. Analogous physical systems can be created on a single chip using superconducting circuits, along with nonlinear Josephson junctions, or metalized flexible membrane capacitors. In this talk, I will discuss our experimental efforts at NIST to utilize parametric interactions to help control different physical processes that are important manipulating quantum information. Harnessing these processes on-chip with superconducting circuit components, including micro-drum mechanical resonators, electromagnetic cavity modes, and superconducting quantum bits provides a highly programmable platform for engineering both closed and open quantum systems for simulation or computation.

Speaker Bio: Ray Simmonds received his BA, MA, and PhD from the University of California, Berkeley in 2002, where he studied Quantum Interfrence in superfluid He-3. After a 2 year post-doc at NIST in Boulder CO developing superconducting quantum bits, he became a staff physicist. His current research is focused on the application of superconducting microwave and optomechanical circuit techniques for quantum information, measurement, and computing.
Timur Tscherbul, University of Nevada Reno

Quantum coherence from thermal noise: From coherent dynamics to non-equilibrium steady states

Quantum coherence from thermal noise: From coherent dynamics to non-equilibrium steady states

Quantum coherence is widely regarded as an essential resource for quantum information processing and quantum sensing. In this talk, I will present an overview of our recent work on the quantum dynamics of noise-induced Fano coherences that occur in multilevel quantum systems interacting with a thermal bath (such as blackbody radiation) in the absence of coherent driving. By solving the nonsecular Bloch-Redfield quantum master equation for a model three-level V-system driven by a thermal bath, we show that Fano coherences exhibit quantum beats when the spacing between the excited states of the V-system is large compared to the radiative decay rates. In the opposite limit of small excited-state spacing, we observe the emergence of non-equilibrium quasi-steady states, which become true non-equilibrium steady states if the thermal driving is polarized. The general theory will be illustrated with two examples involving the time evolution of Fano coherences in Rydberg atoms immersed in blackbody radiation and the breaking of detailed balance in atomic calcium driven by polarized incoherent light. Implications of these results for quantum information processing and quantum thermodynamics will be discussed.

Speaker Bio: Tscherbul Timur earned his PhD from Moscow State University, and received a Killam postdoctoral fellowship at the University of British Columbia. He joined the faculty at the University of Nevada, Reno in 2015 after working as a postdoc at Harvard and the University of Toronto. He is a computational quantum physisist interested in the theory of open quantum systems, quantum dynamics and control of complex atomic and molecular systems, quantum impurity problems, and diagrammatic Monte Carlo methods.
Zhexuan Gong, Colorado School of Mines

Speed limit of entangling gates in quantum computers: Theory and Experiment.

Fast two-qubit entangling gates are essential for quantum computers with finite coherence times. Due to the limit of interaction strength among qubits, there exists a theoretical speed limit for a given two-qubit entangling gate. This speed limit has been explicitly found only for a two-qubit system and under the assumption of negligible single qubit gate time. We propose to demonstrate such speed limit experimentally using two superconducting transmon qubits with an always-on capacitive coupling. Moreover, we investigate a modified speed limit when single qubit gate time is not negligible, as in any practical experimental setup. Finally, we study the generalization to multiple qubit systems where the coupling to additional qubits can significantly increase the speed limit of a two-qubit entangling gate, thus requiring the co-design of the quantum computer from both theorists and experimentalists for optimal gate performance.

Speaker Bio: Zhexuan Gong received his PhD in Physics from the University of Michigan in 2013. He was then a postdoctoral research associate and research scientist at the Joint Quantum Institute, University of Maryland and NIST. He joined Mines in 2018 as an assistant professor and also holds a NIST associate position. His areas of research include quantum computing, quantum information theory, and quantum many-body physics.

Poster Session

NameInstPoster Title
Kirsten BlaggMinesThermoelectric effects in Superconductor Ferromagnetic Hybrids
Jacob CutshallReedA New Form of Quantum Tomography
Mina FasihiMinesComplex network description of phase transitions in the classical and quantum disordered Ising Model
Patrick HarringtonWash U.Photonic transport in quantum metamaterials
Joel HowardMinesInvestigating Entanglement Rates of Coupled Superconducting Qubits
Matthew JonesMinesOpen Source Matrix Product States: A Simulation Platform for Quantum Computing Technologies
Eric JonesMinesVariational preparation of quantum Hall states on a lattice
Sarah JonesMinesEffects of Nanoparticle Size and Density on Vortex Creep in (Y,Gd)BCO Films
Daria KowsariWash U.Memory in non-Markovian Open Quantum Systems
Suyesh KoyuUNRQuantum Coherent Dynamics from Thermal Noise: A Three-level V-system Driven by Incoherent Radiation
Alex LidiakMinesQuantum State Compression and Analysis via Dimensionality Reduction
Brad LloydMinesQuantum Dots in Silicon as a Candidate Platform for Scalable Quantum Computing and Quantum Neuromorphic Devices
Nick MateriseMinesQuantum Heat Engine Simulated on Superconducting Qubits
David Rodriguez PerezMinesVariable Dissipation in Small Logical Qubits
Zhijie TangMinesTheoretical survey of unconventional quantum annealing methods applied to a difficult trial problem
Brooks VenutiMinesProbing Magnetic Skyrmions in the Presence of Disorder
Joshua LewisMinesFractional Calculus in the Analysis of Quantum Systems

Attendees

NameInstitution
Adams, DanielColorado School of Mines
Alberi, KirstinNational Renewable Energy Laboratory
Alrumaih, AmaniColorado School of Mines
Bachman, KateColorado School of Mines
Bauers, SageNational Renewable Energy Laboratory
Beard, MattNational Renewable Energy Laboratory
Beck, MarkReed College
Becker, DylonColorado School of Mines
Been, JoelColorado School of Mines
Bielejec, EdwardSandia National Lab
Blagg, KirstenColorado School of Mines
Brennecka, GeoffColorado School of Mines
Breznay, NicholasHarvey Mudd College
Brooks, JeremyColorado School of Mines
Brown, KirstenColorado School of Mines
Bruce, KaneColorado School of Mines
Bush, BrianNational Renewable Energy Laboratory
Carr, LincolnColorado School of Mines
Chen, XiaowenNational Renewable Energy Laboratory
Chen, XihanNational Renewable Energy Laboratory
Cole, HaleyColorado School of Mines
Collins, ReubenColorado School of Mines
Cutshall, JacobReed College
DeMott, RoswellColorado School of Mines
DeWolf-Moura, TyjalColorado School of Mines
Downie, KhloeColorado School of Mines
Eley, SerenaColorado School of Mines
Fasihi, MinaColorado School of Mines
Fearing, StevenColorado School of Mines
Ferguson, AndrewNational Renewable Energy Laboratory
Giddins, HeatherColorado School of Mines
Godfrey, ChristianColorado School of Mines
Gong, ZhexuanColorado School of Mines
Gorman, BrianColorado School of Mines
Haack, CaseyColorado School of Mines
Halaoui, AdamThe University of Denver
Harrington, PatrickWashington University St. Louis
Honors, DylanColorado School of Mines
Howard, JoelColorado School of Mines
Hurst, HilaryJoint Quantum Institute/San Jose State University
Iverson, GabrielJoint Quantum Institute/San Jose State University
Jameson, CaseyColorado School of Mines
Johnson, JustinNational Renewable Energy Laboratory
Jones, EricColorado School of Mines
Jones, MatthewColorado School of Mines
Jones, SarahColorado School of Mines
Kapit, EliotColorado School of Mines
Kehyias, PauliSandia National Lab
Kelly, BrianColorado School of Mines
Khatami, EhsanSan Jose State University
Kowsari, DariaWashington University St. Louis
Koyu, SuyeshUniversity of Nevada Reno
Kuklin, JacksonColorado School of Mines
Kumar, NitinColorado School of Mines
Lewis, JoshColorado School of Mines
Lewis, RupertSandia National Lab
Lidiak, AlexanderColorado School of Mines
Lloyd, BradleyColorado School of Mines
Lu, Tzu-MingSandia National Lab
Luhman, DwightSandia National Lab
Lusk, MarkColorado School of Mines
Lynn, TheresaHarvey Mudd College
Materise, NickColorado School of Mines
Matlock, CharlesColorado School of Mines
McKinsey, JosephColorado School of Mines
McMullen, SkylerColorado School of Mines
McPherson, AlexandriaColorado School of Mines
McRae, Corey RaeNational Institute of Standards and Technology
Mi, XiaoGoogle
Mikulich, AlexanderColorado School of Mines
Mohammad, MajidColorado School of Mines
Monaghan, AustinColorado School of Mines
Moses, JoshuaColorado School of Mines
Murch, KaterWashington University St. Louis
Niyonkuru, PaulColorado School of Mines
Osella, AnnaNational Renewable Energy Laboratory
Parrott, ZacharyColorado School of Mines
Paver, BrendanColorado School of Mines
Quispe-Flores, CarlaColorado School of Mines
Ramos De Oliveira, JonaColorado School of Mines
Riddle, SamColorado School of Mines
Rodriguez Perez, DavidColorado School of Mines
Sanders, CalebColorado School of Mines
Scalettar, RichardUniversity of California Davis
Schenken, WilliamColorado School of Mines
Schroeter, DarrellReed College
Selinger, AlanColorado School of Mines
Simmonds, RayNational Institute of Standards and Technology
Singh, MeenakshiColorado School of Mines
Smith, ConnorColorado School of Mines
Soto Ramos de Oliveira, JonatanSoto Ramos de Oliveira
Stone, ChuckColorado School of Mines
Supple, EdwinColorado School of Mines
Swirtz, MadisonColorado School of Mines
Tang, ZhijeColorado School of Mines
Tavenner, JacobColorado School of Mines
Tellez Gonzalez, JaimeColorado School of Mines
Torres, AndrewUniversity of Denver
Tscherbul, TimurUniversity of Nevada Reno
Varosy, PaulColorado School of Mines
Venuti, BrooksColorado School of Mines
Wagner, TaylorColorado School of Mines
Walden, MichaelColorado School of Mines
Wiesner, LauraColorado School of Mines
Willner, JacksonColorado School of Mines
Wilson, AlexanderColorado School of Mines
Wu, DavidColorado School of Mines
Zabrocky, MalloryColorado School of Mines
Ziyad, JalanReed College

Lodging and Travel

Workshop lodging will be at Table Mountain Inn and can be arranged through us at quantum@mines.edu.

Plane tickets will be reimbursed for workshop participants coming from outside Colorado, and confirmed speakers or participants should go ahead and purchase those.  Please double check with us at quantum@mines.edu if your cost is over $400.

For getting to Golden, we recommend the easy and reliable lightrail system that leaves directly from the airport:
RTD rail system, Rail System Map
Take the A train from the airport to Union station at the end of the A line. Then transfer to the W train and ride it to the end of the W line in Golden. There is a small bus every 15 minutes that takes you straight downtown from there.

Uber and Lyft are about $60-80 one way. A taxi will cost around $100+. Other alternatives include:
Denvers Airport Transportation
Transit Van Shuttle