Force sensing based on coherent quantum noise cancellation in a hybrid optomechanical cavity with squeezed-vacuum injection

TL;DR

This paper presents a feasible quantum force sensor that uses coherent quantum noise cancellation and squeezed vacuum injection in a hybrid atom-cavity optomechanical system to detect weak forces below the standard quantum limit across a broad frequency range.

Contribution

It introduces a novel experimental scheme combining CQNC and squeezed vacuum injection in a hybrid setup for enhanced force sensing.

Findings

Achieves sub-SQL sensitivity over a wide frequency band

Reduces input laser power needed for high sensitivity

Demonstrates exact cancellation of back-action noise via atomic ensemble

Abstract

We propose and analyse a feasible experimental scheme for a quantum force sensor based on the elimination of back-action noise through coherent quantum noise cancellation (CQNC) in a hybrid atom-cavity optomechanical setup assisted with squeezed vacuum injection. The force detector, which allows for a continuous, broad-band detection of weak forces well below the standard quantum limit (SQL), is formed by a single optical cavity simultaneously coupled to a mechanical oscillator and to an ensemble of ultracold atoms. The latter acts as a negative-mass oscillator so that atomic noise cancels exactly the back-action noise from the mechanical oscillator due to destructive quantum interference. Squeezed vacuum injection enforces this cancellation and allows to reach sub-SQL sensitivity in a very wide frequency band, and at much lower input laser powers.