# Twofold mechanical squeezing in a cavity optomechanical system

## TL;DR

This paper demonstrates a novel two-fold squeezing mechanism in a cavity optomechanical system combining parametric amplification and periodic modulation, enhancing control over mechanical quantum states for sensing applications.

## Contribution

It introduces a new method for achieving enhanced mechanical squeezing by combining parametric driving with periodic modulation in an optomechanical cavity system.

## Key findings

- Two-fold squeezing surpasses single-method limits.
- Enhanced suppression of mechanical quadrature fluctuations.
- Potential for ultrasensitive force and motion sensing.

## Abstract

We investigate the dynamics of an optomechanical system where a cavity with a movable mirror involves a degenerate optical parametric amplifier and is driven by a periodically modulated laser field. Our results show that the cooperation between the parametric driving and periodically modulated cavity driving results in a two-fold squeezing on the movable cavity mirror that acts as a mechanical oscillator. This allows the fluctuation of the mechanical oscillator in one quadrature (momentum or position) to be reduced to a level that cannot be reached by solely applying either of these two drivings. In addition to the fundamental interests, e.g., study of quantum effects at the macroscopic level and exploration of the quantum-to-classical transition, our results have potential applications in ultrasensitive sensing of force and motion.