Quantum Engineering Seminar
Thursday, November 3, 2022 @ 10:00 AM MST
Marquez Hall 126
 
 
Daniel Slichter
NIST
 
Daniel Slichter

LASER-FREE ENTANGLEMENT AND SQUEEZING WITH TRAPPED IONS

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Abstract: Trapped atomic ions in vacuum are a leading platform for quantum computing, sensing, and networking, thanks in part to their excellent coherence properties and the ability to manipulate and measure their quantum states with high fidelity. While quantum state manipulation in trapped ions typically relies on high-performance laser systems, our group is working to demonstrate high-fidelity control of trapped ions with rf/microwave magnetic and electric fields and gradients, with the goal of improving both performance and scalability. I will describe some recent results, including microwave/rf-based generation of entangled Bell states of ion spin with fidelity on par with that of the best laser-based demonstrations, and the use of laser-free trap potential modulation to perform strong unitary squeezing of ion motion, enabling sensing of electric fields below the standard quantum limit and enhancement of motion-mediated ion-ion entangling interactions. I will conclude by providing some perspectives on how laser-free control may offer advantages for large-scale trapped ion quantum computing.

 

Bio: Daniel Slichter is a staff physicist at in the Ion Storage Group at NIST in Boulder, CO. His research focuses on quantum information experiments with trapped atomic ions, with an emphasis on developing new paradigms for scalable trapped ion quantum computing and networking. Recent projects include performing high-fidelity entangling operations with microwave and rf fields instead of lasers; using strong unitary squeezing of ion motion to enhance ion-ion interactions and to perform electric field sensing below the standard quantum limit; and integrating superconducting photon detectors into microfabricated ion traps as an initial step in building a fully chip-integrated trapped ion quantum processor. Prior to NIST, he conducted research in superconducting quantum information, where he performed the first continuous high-fidelity measurement of a superconducting qubit, studied quantum feedback and measurement backaction, and worked on the development of near-quantum-limited microwave-frequency superconducting parametric amplifiers.

 

September 26 @ 11AM in CK282
RAYMOND SIMMONDS
NIST
Special QE Seminar: Engineering Parametric Interactions Between Superconducting Circuits
Abstract: Over 15 years ago, parametric coupling was proposed as a way to entangle flux qubits at their “sweet spots” with frequencies that were far detuned from each other. This was a possible solution to the difficulty with optimizing the spectrum of flux qubits that were extremely sensitivity to the variations in the critical current of their smallest fabricated Josephson junctions. After one major demonstration, this strategy was soon abandoned. In contrast, ion trap systems have always relied on parametric interactions that are naturally more flexible, allowing all-to-all tunable coupling between individual qubits. Over a decade ago, our group at NIST (in Boulder, CO) revived the parametric coupling strategy as a powerful tool for engineering interactions between superconducting circuits. In this talk, I will explain our parametric ideology and highlight our group’s continued efforts to develop non-resonant, parametrically induced coupled interactions between transmon-based qubits and cavities to enable fast, high fidelity gate operations and measurements. Finally, I’ll discuss improving, connecting, and expanding these systems for constructing analog quantum simulators or processing quantum information.