Nanomechanical squeezing with detection via a microwave cavity

TL;DR

This paper explores how a parametrically-driven nanomechanical resonator coupled to a microwave cavity can achieve quantum squeezing of its motion and the microwave field, especially near the ground state, using sideband driving techniques.

Contribution

It introduces a formalism for analyzing microwave and mechanical squeezing via sideband drives in a coupled resonator-cavity system, including finite temperature effects.

Findings

Squeezing spectra are calculated for various driving conditions.

Squeezing of the microwave output field can infer nanoresonator squeezing.

Both red and blue sideband drives are analyzed for their effects.

Abstract

We study a parametrically-driven nanomechanical resonator capacitively coupled to a microwave cavity. If the nanoresonator can be cooled to near its quantum ground state then quantum squeezing of a quadrature of the nanoresonator motion becomes feasible. We consider the adiabatic limit in which the cavity mode is slaved to the nanoresonator mode. By driving the cavity on its red-detuned sideband, the squeezing can be coupled into the microwave field at the cavity resonance. The red-detuned sideband drive is also compatible with the goal of ground state cooling. Squeezing of the output microwave field may be inferred using a technique similar to that used to infer squeezing of the field produced by a Josephson parametric amplifier, and subsequently, squeezing of the nanoresonator motion may be inferred. We have calculated the output field microwave squeezing spectra and related this to squeezing of the nanoresonator motion, both at zero and finite temperature. Driving the cavity on the blue-detuned sideband, and on both the blue and red sidebands, have also been considered within the same formalism.