Force Sensing Beyond the Standard Quantum Limit in a Hybrid Optomechanical Platform

TL;DR

This paper proposes a hybrid optomechanical system with quantum dots and an optical parametric amplifier that can surpass the standard quantum limit in force sensing by canceling back action noise and enhancing sensitivity.

Contribution

It introduces a novel hybrid setup combining quantum dots and an OPA to improve force measurement sensitivity beyond the SQL.

Findings

Quantum noise spectral density is modified by QD response and nonlinearity.

Coherent quantum noise cancellation can eliminate back action noise.

Sensitivity beyond the SQL is achieved at lower laser power.

Abstract

We theoretically investigate quantum measurement noise in a hybrid optomechanical system, focusing on radiation pressure back action and its impact on force sensing. The setup consists of an optomechanical cavity with a movable mirror, a fixed semi transparent mirror, an ensemble of quantum dots (QD) coupled to the cavity mode, and an intracavity optical parametric amplifier (OPA). We show how the QD induced response, together with the system nonlinearity, modifies the noise spectral density and thereby improves the force measurement sensitivity. In this setup, coherent quantum noise cancellation (CQNC) can completely remove the back action noise. In addition, increasing the OPA pump gain enables sensitivity beyond the standard quantum limit (SQL) at reduced laser power. These combined effects allow weak force sensing beyond the SQL.