Overwhelming thermomechanical motion with microwave radiation pressure shot noise

TL;DR

This paper demonstrates that microwave radiation pressure shot noise can dominate thermal motion in a cavity optomechanical system, revealing the fundamental quantum limits of measurement.

Contribution

It provides the first experimental observation of quantum backaction overwhelming thermal motion in a microwave optomechanical setup.

Findings

Quantum backaction exceeds thermal motion by 24 dB.

Measurement imprecision and backaction trade-off at the quantum limit.

Observation of the standard quantum limit in a microwave cavity system.

Abstract

We measure the fundamental noise processes associated with a continuous linear position measurement of a micromechanical membrane incorporated in a microwave cavity optomechanical circuit. We observe the trade-off between the two fundamental sources of noises that enforce the standard quantum limit: the measurement imprecision and radiation-pressure backaction from photon shot noise. We demonstrate that the quantum backaction of the measurement can overwhelm the intrinsic thermal motion by 24 dB, entering a new regime for cavity optomechanical systems.