Enhanced Cooperativity in a Near-Quantum Microwave-to-Optical Transducer

Abstract:

In this thesis, I describe the development of a microwave-to-optical transducer mediated by a mechanical resonator that is capable of frequency converting quantum signals with applications for quantum networking. Despite the transducer's record efficiency, continuous operation, and low noise, microwave pump-induced heating effects prevent quantum-enabled performance. These effects can be modelled with a bath of two-level-system-like defects and, critically, improved dramatically by annealing. In combination with enhanced cooperativity between the microwave circuit, mechanical mode, and optical cavity, this transducer is poised to convert quantum signals between these two frequency domains with high fidelity in the near future.