Quantum Engineering Graduate Seminar Series Spring 2023

Unless specified otherwise, all seminars will take place in CoorsTek 282 on Tuesday at 10:00AM.

02/14 Non-academic options for physics graduates in quantum technology
Unless specified otherwise, all seminars will take place in CoorsTek 282 on Tuesday at 10:00AM.
Josh West
Non-academic options for physics graduates in quantum technology

Abstract: In the ~12 years since graduating with a Ph.D., I have worked in a myriad of scientific instrument development projects centered around quantum technologies. Most broadly, these could be categorized as cryogenic systems for superconducting electronics. Some are for quantum computing, others are used for astronomy, particle physics, or other scientific applications. I will give an overview of the types of products we sell, some of the skillsets that we look for when hiring, and some examples of previous School of Mines students that are working within our organization.

Bio: Josh West is the Senior Director of the Cryogenic Products Group at High Precision Devices in Boulder, CO. He received a Ph.D. in Physics from Penn State University in 2010.

0207 Listening to Quantum Sound
Josh West
Listening to Quantum Sound

Abstract: Quantum mechanics is traditionally considered when measuring at the extreme microscopic scale, i.e. single photons, electrons or atoms. However, even the early pioneers of the quantum theory postulated gedanken experiments in which quantum effects would manifest on an everyday scale. I will present recent experiments in which we engineer and measure microelectromechanical (MEMs) circuits to observe and to exploit quantum behavior at an increasingly macroscopic scale. By embedding mechanical resonators in superconducting microwave circuits, we achieve strong radiation-pressure coupling between fields and motion that allows us to perform quantum experiments of massive objects. I will present our recent experimental demonstration of deterministic macroscopic entanglement, as well as ongoing efforts toward arbitrary quantum control of mechanical systems. The ability to prepare and to “listen” to quantum sound has implications for fundamental science as well as many powerful applications including the processing, storage and networking of quantum information.

Bio: Dr. John D. Teufel is an experimental physicist in the Applied Physics Division of NIST Boulder. He received his PhD in physics from Yale University on a fellowship from NASA studying superconducting photon detectors. Now as a project leader in the Advanced Microwave Photonics group at NIST, he uses the tools of nanofabrication and precision microwave measurements at cryogenic temperatures to explore the quantum behavior of macroscopic systems. This includes development and metrology of superconducting qubits, optomechanical circuits and Josephson parametric technology.

01/31 Quantum Software, VQA’s, FTQC compilations, Resources Estimation, and careers in quantum computing
Quantum Software, VQA’s, FTQC compilations, Resources Estimation, and careers in quantum computing
01/24 TKET: Quantinuum’s advanced quantum SDK for the NISQ era
TKET: Quantinuum’s advanced quantum SDK for the NISQ era

Quantinuum is one of the world’s largest full-stack quantum computing companies integrating hardware and software, such as the open-source quantum software development kit called “TKET” (https://github.com/CQCL/tket). TKET is written in C++ and Python for developing and executing gate-level quantum computation. It automatically handles many of the intricacies of NISQ technology. For example, TKET provides state-of-the-art circuit compilation and optimization performance, facilitating platform-agnostic software development and allowing code reuse. In this presentation, I will provide a comprehensive, feature-focused tour of pyTKET, the Python module for interfacing with TKET. Additionally, I will discuss TKET’s extension modules for interfacing with other hardware and software modules and briefly discuss TKET’s performance.

Dr. Kathrin Spendier

Bio: Dr. Kathrin Spendier is a Quantum Evangelist at Quantinuum, where she focuses on promoting the company’s cutting-edge TKET software development kit. She holds a Ph.D. in Physics with distinction from the University of New Mexico. After a year as a Research Associate, Dr. Spendier joined the University of Colorado Colorado Springs (UCCS) as a tenure-track faculty in Physics. She earned tenure by researching biophysical phenomena using super-resolution microscopy techniques and condensed matter physics. She also developed and taught numerous physics undergraduate and graduate courses. After joining Quantinuum, she remains an Associate Professor with a research affiliation at UCCS.

01/17 Investigating quantum speed limits with superconducting qubits
Quantum Engineering Program and Dept. of Physics, Colorado School of Mines
Investigating quantum speed limits with superconducting qubits

The speed at which quantum entanglement between qubits with short range interactions can be generated is limited by the Lieb-Robinson bound. Introducing longer range interactions relaxes this bound and entanglement can be generated at a faster rate. The speed limit for this has been explicitly found theoretically only for a two-qubit system and under the assumption of negligible single qubit gate time. We seek to demonstrate such a speed limit for entanglement experimentally using two superconducting transmon qubits. Additionally, we aim to measure how much entangling gates can be sped up by introducing additional qubits coupled to the first two. Since the speed up depends on additional entangled qubits, it is expected to increase as the system size grows. This has important implications for large-scale quantum computing.

Spring 2022

March 1, 2022, 4:00 PM – 5:00 PM, CoorsTek 140/150


Abstract: Decades of progress in trapped ion quantum computing across academia, government labs, and industry enabled some of the world’s highest performing systems, improving our understanding of how to move forward in this emerging technology. Quantinuum is pursuing the quantum charge-coupled device (QCCD) architecture of trapped ion quantum computing and recently developed advancements in basic primitive operations of the architecture, ion transport, logical gates, and qubit initialization and detection, helping to define hardware for the next generation quantum computers. In parallel research tracks, current systems are used to gather crucial information about application performance in the areas of quantum error correction and simulations of quantum dynamics.

Biography: Dr. Russell Stutz is currently leading the Commercial Products group of HQS, where he is responsible for the design and build of commercial quantum computers. He received his Bachelor of Science in Physics from the University of Kansas, taking a commission in the US Air Force through the ROTC program upon graduation. As an Air Force officer, he worked on laser research at the Air Force Research Lab, Directed Energy Directorate at Kirtland AFB, NM. Dr. Stutz received his PhD from the University of Colorado-Boulder in atomic, molecular, and optical physics in 2010 under the tutelage of his research advisor Eric Cornell. After receiving his PhD, Dr. Stutz has worked industrial research and development at AOSense, a small company in California developing quantum sensors, as well as Lockheed Martin in Colorado. He has been with Honeywell since 2016, and was one of the first employees at the Broomfield, CO site.

March 29, 2022, 4:00 PM – 5:00 PM, CoorsTek 140/150
CTO and Founder of Atom Computing, Boulder, CO

An Old Qubit Contender Becomes New Again: Neutral Atoms

Neutral atoms trapped in optical tweezers are a promising platform for implementing scalable quantum computers. Here I introduce a system with the ability to individually manipulate a two-dimensional array of nuclear spin qubits. Each qubit is encoded in the ground state manifold of 87Sr and is individually addressable by site-selective beams. We observe negligible spin relaxation after 5 seconds, indicating that T1 ≫ 5 s. We also demonstrate significant phase coherence over the entire array, measuring T2 = (21 ± 7) s. Capitalizing on these beneficial properties of our optical tweezer platform, we aim to scale this system to a larger array of qubits in a parallelizable manner. Furthermore, these qubits can be entangled utilizing site-selective Rydberg excitation creating a universal gate set.

Ben received his PhD at the University of Colorado Boulder where he worked on Optical Atomic Clocks. Afterwards he worked at Intel on classical computers, at Rigetti on Superconducting Josephson Junctions, and in 2018 founded Atom Computing. He is the CTO of Atom Computing directing R&D efforts both on current systems as well as future systems being built at Atom.

March 31, 2022, 11:00 AM, Marquez 210
CEO & Cofounder, Vescent Photonics LLC, Golden CO, USA

Quantum Systems Will Change the World (Again), But Not Without Photonics and Not Without Colorado Talent

When systems are engineered to relay or extend “quantum weirdness” from the nanoscopic scale of atoms to the macroscopic scale of humans amazing things can happen. Twentieth century quantum systems (the transistor and the laser) ushered in the computer age and the information age, which changed the world. Twenty-first century quantum systems is just emerging, and the disruptive potential is equally tantalizing. Almost all these emergent quantum systems require lasers and photonics, representing both an opportunity and a challenge. In this talk I will discuss the complexity of the lasers-for-quantum space, present the technical and economic landscape, and pose possible paths forward for how lasers and photonics can usher in a new quantum age. I will also present how Vescent, a local company, is playing a critical role in this development and discuss how Colorado talent, at Vescent and in other Colorado Companies, is enabling the quantum 2.0 revolution.

APRIL 8-9, 2022

April 12, 2022, 4:00 PM – 5:00 PM, Zoom
University of Oregon, Department of Physics


Abstract: Entanglement, the correlations displayed between sub- systems of a multipartite quantum system, is one of the most distinguishing properties of quantum physics and a significant resource for quantum information science and technology. Entanglement swapping is a protocol that enables entanglement of quantum systems that have never interacted. This protocol underpins efforts to realize large-scale quantum networks as the core element of quantum repeaters. Entanglement swapping between entangled photons has been experimentally demonstrated using photons entangled in their polarization, spatial, and temporal degrees of freedom. Here we focus on encoding information in the spectral-temporal mode of single photons. This allows for a multiplexed approach to entanglement swapping that can generate many different entangled two-photon states. The entanglement swapping protocol relies on multimode entangled photon-pair sources and the ability to perform spectrally-resolved single-photon detection. Experimental results demonstrating the generation of 5 nearly-orthogonal two-photon states is presented.

Biography: Brian J. Smith is Professor of Physics at the University of Oregon, where he leads the Optical Quantum Technologies (OQT) research group. Prior to this Dr Smith was Associate Professor of Experimental Quantum Physics in the Department of Physics at the University of Oxford from 2010 to 2016. He was a Senior Research Scientist at the National University of Singapore 2009-2010, where he worked on integrated quantum photonics, and quantum-enhanced sensing. He was a Royal Society Postdoctoral Fellow 2007-2009 at the University of Oxford where he worked on controlled photonic quantum state preparation and manipulation, quantum measurement characterization, and quantum-enhanced sensing. He obtained a PhD in Experimental Quantum Optics from the University of Oregon in 2007 and BA degrees in Physics and Mathematics from Gustavus Adolphus College in 2000. Smith’s current research interests lie in the general areas of quantum optics and quantum technologies and their use in probing fundamental quantum physics and realizing quantum-enhanced applications with performance beyond that possible with classical resources. In these fields he has developed approaches for producing non-classical states of light with well-defined mode structure based upon engineered nonlinear optics, methods to coherently manipulate such quantum states, and efficient means to measure the resultant states. Recently his efforts have focused on harnessing the temporal-spectral mode structure of light to enable realization of larger quantum systems. These quantum-optical tools have enabled him to examine fundamental questions in quantum physics, such as the commutation relations for creation and annihilation operations, and experimentally address various quantum-enhanced technologies, for example quantum-enhanced sensing and quantum communications.

Current research: Smith’s current research interests lie in the general areas of quantum optics and quantum technologies and their use in probing fundamental quantum physics and realizing quantum-enhanced applications with performance beyond that possible with classical resources. In these fields he has developed approaches for producing non-classical states of light with well-defined mode structure based upon engineered nonlinear optics, methods to coherently manipulate such quantum states, and efficient means to measure the resultant states. Recently his efforts have focused on harnessing the temporal-spectral mode structure of light to enable realization of larger quantum systems. These quantum-optical tools have enabled him to examine fundamental questions in quantum physics, such as the commutation relations for creation and annihilation operations, and experimentally address various quantum-enhanced technologies, for example quantum-enhanced sensing and quantum communications.

Lecture via Zoom

April 19, 2022, 4:00 PM, Zoom
University of Michigan, Department of Electrical Engineering & Computer Science


Abstract: Gallium nitride (GaN) semiconductors are best known for their revolutionary applications in creating significant energy savings for electric lights (Nobel Prize in Physics 2014). Unlike silicon and the majority of other compound semiconductor materials, GaN is piezoelectric due to its wurtzite symmetry which is noncentrosymmetric. The piezoelectricity creates an electric potential when the material is strained. The piezoelectric potential can cause the electrons and holes to be separated from each other, which is disadvantageous to their radiative recombination efficiency. However, if properly engineered, the piezoelectric potential can enable a suite of applications for future augmented reality, robotics, health care, and quantum information technologies. In this talk, I will introduce the idea of local strain engineering which allows us to engineer the piezoelectric potential in a nanometer length scale by using the GaN nanostructures. I will discuss how the nanostructure’s geometry can be used as a tuning knob to control the optical properties of the material. A simple theoretical model will be presented that can be easily adapted for device design. I will also give a brief overview on various potential applications with the main focus on quantum photonics.

Biography: P.C. Ku received his BS from the National Taiwan University and PhD from the University of California at Berkeley, both in electrical engineering. He was awarded the Ross Tucker Memorial Award in 2004 as a result of his PhD research. He was with Intel before joining the University of Michigan where he is currently a professor of electrical engineering and computer science. In 2010, he cofounded Arborlight that was dedicated to solid-state lighting system design and application. He received the DARPA Young Faculty Award in 2010.

Lecture via Zoom

For links to other quantum-related events, news, job opportunities, etc, check out PhD Physics student Farai Mazhandu’s Quantum@Mines Newsletter.



Fall 2021
Colorado School of Mines, Department of Physics
November 16, 2021

The Center for Nonlinear Studies and Los Alamos National Laboratory
October 28-30, 2021
This workshop will be held in-person at the Drury Plaza Hotel in
Santa Fe, NM for those vaccinated against COVID-19 and will be broadcast to virtual participants. You must apply to attend in-person or register as a virtual attendee on the website in advance of the workshop.

University of South Florida
September 3, 2021
10:00 AM ET
Online via Microsoft Teams

August 27, 2021
1-2:30 PM ET

Spring 2021
University of Wisconsin, Madison, Department of Physics


Quantum computing is based on the manipulation of two-level quantum systems, or qubits. In most approaches to quantum computing, qubits are as much as possible isolated from their environment in order to minimize the loss of qubit phase coherence. The use of nuclear spins as qubits is a well-known realization of this approach. In a radically different approach, quantum computing is also possible for strongly coupled multi-electron spin 1/2 systems, as realized in silicon-based devices. In this talk I will present both a historical overview of how quantum manipulation in silicon has developed, as well as the latest results from both our group at Wisconsin and from around the world. I will discuss our recent demonstration of coherent manipulation of eight different microwave-frequency resonances in a single silicon quantum dot, which starts to glimpse the future prospect of spin qubits being controlled using the types of powerful tools developed for controlling atoms by the AMO community over many decades. I will end with a brief discussion of how silicon fits into the broad quantum science and technology ecosystem, which is growing at an astounding rate. This article in Physics Today discusses closely related material: Quantum computing with semiconductor spins. Bio: Mark A. Eriksson is the John Bardeen Professor of Physics at the University of Wisconsin-Madison. He received a B.S. with honors in physics and mathematics in 1992 from the University of Wisconsin-Madison and an A.M. (1994) and Ph.D. (1997) in physics from Harvard University. His Ph.D. thesis demonstrated the first cryogenic scanned-gate measurements of a semiconductor nanostructure. He was a postdoctoral member of technical staff at Bell Laboratories from 1997-1999, where he studied ultra-low-density electron systems. Eriksson joined the faculty of the Department of Physics at UW-Madison in 1999. His research has focused on quantum computing, semiconductor quantum dots, and nanoscience. With collaborators he demonstrated the first quantum dot in silicon/silicon-germanium occupied by an individual electron and performed the first experiments to demonstrate the quantum dot hybrid qubit. Eriksson currently leads a multi-university team focused on the development of spin qubits in gate-defined silicon quantum dots. A goal of this work is to enable quantum computers, which manipulate information coherently, to be built using many of the materials and fabrication methods that are the foundation of modern, classical integrated circuits. Eriksson was elected fellow of the American Physical Society in 2012 and of the American Association for the Advancement of Science in 2015. All lectures are via Zoom

University at Buffalo, Department of Physics


Electron spin qubits in Si are promising candidates as building blocks toward future scalable quantum computers. Tremendous progress has been made in the past decade in demonstrating the exceptional coherence properties of spins confined in quantum dots and donors. However, studies of high-fidelity manipulation of spin qubits have encountered numerous problems as well: for donors, the small Bohr radius makes donor electrons hard to locate and control; for quantum dots, especially ones in Si/SiGe heterostructures, small valley splitting makes spin detection based on spin blockade difficult to realize. In this talk I discuss our recent work on spin manipulation and decoherence in Si quantum dots. I will first show that the complex valley-orbit coupling in a Si quantum dot can be significantly impacted by the atomistic scale features of an interface. The different valley mixing angles across a double dot would remove all valley selection rules in electron tunneling, and cause significant modification to the two-electron exchange coupling. On the decoherence front, I will discuss our recent study of spin relaxation in a Si quantum dot under the influence of a micromagnet that allows electrical control of single spins in Si. We show that the field gradient generated by a micromagnet amounts to an artificial spin-orbit interaction. However, unlike intrinsic spin-orbit coupling, which causes only spin relaxation, a micromagnet would cause both spin relaxation and pure dephasing, and generate a longitudinal effective field that could potentially be used for spin manipulation. We thank support by US ARO. Short Bio: Xuedong Hu is a physics professor at the University at Buffalo, the State University of New York. He received his PhD degree in condensed matter theory from University of Michigan in 1996, supervised by Franco Nori. He was introduced to the field of solid state quantum information processing in 1998 as a postdoc in Sankar Das Sarma’s group at the University of Maryland. His recent research focus is on spin qubits in silicon.

Monday–Friday, March 15–19, 2021, virtual APS March Meeting 2021

March 2, 2021, virtual
University of Colorado @ Boulder, JILA


Quantum science with neutral atoms has seen great advances in the past two decades. Many of these advances follow from the development of new techniques for cooling, trapping, and controlling atomic samples. As one example, the technique of optical tweezer trapping of neutral atom arrays has been a powerful tool for quantum simulation and quantum information, because it enables control and detection of individual atoms with switchable interactions. In this talk, I will describe ongoing work at JILA where we have explored a new direction for the optical tweezer platform: metrology. I will report our recent progress towards combining scalability and quantum coherence in a tweezer-based optical atomic clock platform, and our efforts towards using quantum information concepts and many-body dynamics to create entangled states that enhance metrological performance. Much of this technology is based in the use of tweezer-trapping of a new family of atoms, alkaline-earth atoms — I will discuss the broader outlook of this direction and new pursuits on the horizon. Recorded Video Link Tweezing a New Kind of Atomic Clock Bio: Dr. Adam Kaufman is an associate JILA fellow and assistant professor adjoint at CU Boulder. He did his PhD at JILA, studying few-body quantum mechanics of atoms in optical tweezers. Afterwards, as a postdoctoral fellow at Harvard, he investigated the dynamics of entanglement in thermalizing many-body systems and other Bose-Hubbard phenomena. In 2017, he moved back to JILA where he has continued working in the field of quantum science with neutral atoms. He is a winner of the prestigious APS DAMOP thesis prize in 2016, and he pioneered the research on atomic clocks based on optical tweezers.

February 25-26, 2021, virtual NSF Workshop on Quantum Engineering Education

Fall 2020


Colorado School of Mines
Denver University


 Hydrodynamic whirlpools have fascinated scientists for centuries, seeking to understand their individual structure, stability, and the ways in which they interact with one another. Who hasn’t marveled at tornadoes or watched as soap bubbles get sucked into the vortex of a bathtub drain? To reduce ideas to their essence, such fluid vortices are often considered in a two-dimensional setting where they amount to current swirling around a singularity. These, in turn, bear a striking resemblance to cross-sections of optical vortices that can be created with lasers, but with the propagation axis now treated as time. The vortex center is a then a dark spot about which the phase of light rotates like a barber shop sign. Such engineered light can therefore be interpreted as a two-dimensional, compressible fluid, and the vortices it harbors exhibit all sorts of odd and potentially useful behavior. For instance, optical vortices can attract, repel, scatter, and even annihilate one another. Even more intriguing, these two-dimensional topological objects have a lot in common with the macroscopic quantum states of Bose-Einstein condensates and fractional quantum Hall systems. Pairs can even be used in Bell tests to demonstrate lack of local realism. This motivates a serious consideration of optical vortices as quantum objects that might be harnessed in emerging quantum information technologies. With these deeper issues in mind, our colloquium lecture is intended to serve as an introduction to optical vortices and their classical few-body dynamics. We tag-team an experimentalist and a theorist to provide a fuller perspective of what makes this form of light so interesting.

University of New South Wales


Silicon is an attractive materials platform for developing large-scale quantum computers because of its compatibility with classical silicon electronics and its potential for scalability. This talk will discuss qubits made from quantum dots with multiple electrons in silicon/silicon-germanium heterostructures. These qubits can be manipulated on nanosecond time scales, and their coherence can be extended greatly by appropriate manipulation protocols. They can be tuned so that additional quantum resonances appear that can be driven coherently, which we show is consistent with effects arising form strong electron-electron interactions. Thus, these multi-electron qubits are interesting both as building blocks for quantum computers and as testbeds for investigating strongly interacting electrons. Recorded Video Link

August 13, 2020, virtual 6th Front Range Advanced Magnetics Symposium (FRAMS)

May 26, 2020, virtual Open Quantum Frontier Institute Virtual Workshop: Quantum Education 2nd workshop of the Open Quantum Frontier Institute

April 13-14, 2020 Dr. Zaira Nazario IBM Dr. Nazario will present on quantum computing. CANCELLED

February 28, 2020, 2-3 pm in CoorsTek 282 Fernando Sols Universidad Complutense de Madrid Departamento de Física de Materiales

Protected cat states in a driven superfluid boson gas

We investigate the behavior of a one-dimensional Bose-Hubbard gas in both a ring and a hard-wall box, whose kinetic energy is made to oscillate with zero time average, which suppresses first-order particle hopping while allowing even higher-order processes [1]. At a critical value of the driving, the system passes from a Mott insulator to an exotic superfluid phase. The system in the ring has similarities to the Richardson pairing model which can be exploited to understand key features of the interacting boson problem [2]. The superfluid ground state is a macroscopic quantum superposition, or cat state, of two many-body states characterized by the preferential occupation of opposite momentum eigenstates. Interactions give rise to a reduction (or modified depletion) cloud that is common to both macroscopically distinct states. Symmetry arguments permit a precise identification of the two orthonormal many-body branches forming the ground state. In the ring, the system is sensitive to variations of the effective flux but in such a way that the macroscopic superposition is preserved. We discuss other physical aspects that contribute to protect the catlike nature of the ground state. [1] G. Pieplow, F. Sols, C. E. Creffield, New J. Phys. 20, 073045 (2018). [2] G. Pieplow, C. E. Creffield, F. Sols, Phys. Rev. Research 1, 033013 (2019).

February 21-22, 2020 at the Colorado School of Mines in Golden, CO Open Quantum Frontier Institute 1st workshop of the Open Quantum Frontier Institute

September 16-17, 2019 in Alexandria, VA Quantum Simulators: Architectures and Opportunities US NSF-supported workshop See more on the Quantum Engineering @ Mines Workshops page link.

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