Jun 5 (Wed) @ 11:30am: “Surface Acoustic Waves Integrated with Solid-State Single Photon Sources and Superconducting Electronics,” Michael Choquer, ECE PhD Defense

Zoom Meeting – https://ucsb.zoom.us/j/85158988362?pwd=anR5eW9wYTYzR0R4eld5TEpacVFhZz09

Abstract

Quantum interconnects—devices or processes that transfer quantum information between distinct physical degrees of freedom—are an essential component of many future quantum technologies. The promise of quantum interconnects to preserve fragile quantum states across vast frequency ranges and long distances would open many opportunities for distributing quantum information between spins, phonons, and photons. A variety of approaches are being investigated to connect such systems; recently, elastic waves, and in particular surface acoustic waves (SAWs), have become a versatile tool for controlling individual artificial atoms, including microwave-frequency superconducting qubits and optical-frequency quantum emitters. However, the coupling of SAWs and optically active systems is lagging the current state-of-the-art with SAWs and microwave-frequency superconducting circuits. This research aims to address this technology gap by combining superconducting and optical qubit systems with SAW resonators to mediate coherent interactions between microwave and optical frequency quantum systems. This thesis focuses on two leading quantum emitter platforms—semiconductor quantum dots (QDs) and defect-based quantum emitters in van der Waal materials (vdWMs). Developing a new heterogeneous platform—the first demonstration of strong piezoelectric lithium niobate integrated with both superconducting electronics and III/V semiconductors—SAW resonators with high internal quality factors Qi > 16,000 were demonstrated, and photoluminescence of the QD emission showed evidence of both strain-based SAW modulation of the QD exciton as well as acoustoelectric carrier injection. Experiments with vDWM emitters showed SAW modulation with some of the highest demonstrated strain sensitivities, as well as novel phenomena, including the mixing of excitonic states, which provides a path towards entangled photon pair generation from vDWMs. Further experiments will probe a new set of novel optomechanical devices designed to maximize the optomechanical interaction strength and with the SAW resonator cryogenically cooled to its quantum ground state, moving towards the quantum regime of SAW-quantum emitter optomechanics.

Bio

Michael Choquer received his B.Sc. in electrical and computer engineering from the University of Washington, Seattle in 2018 and M.Sc. in electrical and computer engineering from the University of California, Santa Barbara in 2021. Michael is a Ph.D. candidate in the group of Assistant Professor Galan Moody in the Department of Electrical and Computer Engineering at the University of California, Santa Barbara.  Michael's current research interests include the design, fabrication, and characterization of quantum photonic and phononic devices, including quantum emitters heterogeneously integrated with mechanical resonators.

Hosted by: Professor Galan Moody, Quantum Photonics Lab

Submitted by: Michael Choquer <michaelchoquer@ucsb.edu>