Quantum backaction evading measurements of a silicon nitride membrane resonator

Abstract

Quantum backaction disturbs the measurement of the position of a mechanical oscillator by introducing additional fluctuations. In a quantum backaction measurement technique, the backaction can be evaded, although at the cost of losing part of the information. In this work, we carry out such a quantum backaction measurement using a large 0.5 mm diameter silicon nitride membrane oscillator with 707 kHz frequency, via a microwave cavity readout. The measurement shows that quantum backaction noise can be evaded in the quadrature measurement of the motion of a large object.

A Novel Architecture for room temperature microwave optomechanical experiments

“…One can benefit by coupling mechanical resonators to 3D microwave cavities with low loss. In a recent work by Liu et al [25], backaction evading measurements of a silicon nitride membrane resonator were performed via coupling it to a 3D Cu cavity. They observed a cavity quality factor of 15,000 at 300 mK.…”