Quantum Electromechanics with Drum Resonators
June 13th, 2019 MIKA SILLANPAA Aalto University

Aluminum drumhead resonators coupled to superconducting microwave resonators have been one of the leading platforms to go deep in the quantum limit of mechanical vibrations. I will discuss our recent experiments, where we observe “ponderomotive” cavity optomechanical squeezing of microwaves emitted from our device, as well as find a way to reveal quantum correlations that are hidden in usual detection techniques. The ponderomotive squeezing arises from the fact that under a strong quantum measurement, the motion of a resonator is disturbed by the measurement back-action, as required by the Heisenberg uncertainty principle. When a mechanical resonator is continuously monitored, the back-action is manifest by the shot noise of incoming photons that becomes imprinted onto the motion of the resonator. Following the photons leaving the cavity, the correlations appear as squeezing of quantum noise in the emitted field. Under a strong measurement, the emitted field develops complex-valued quantum correlations, which in general are not completely accessible by standard homodyne measurements. We recover these hidden correlations, using a phase-sensitive measurement scheme employing two local oscillators. The utilization of hidden correlations presents a step forward in the detection of weak forces.

Seminar, June 13, 2019, 12:00. ICFO’s Seminar Room

Hosted by Adrian Bachtold