Steady-state mechanical squeezing and ground-state cooling of a Duffing anharmonic oscillator in an optomechanical cavity assisted by a nonlinear medium

TL;DR

This paper theoretically investigates a hybrid optomechanical system with a nonlinear medium, demonstrating steady-state mechanical squeezing and ground-state cooling of a Duffing anharmonic oscillator, enhanced by optical and mechanical nonlinearities.

Contribution

It provides analytical conditions for multistability and shows how nonlinearities enable mechanical squeezing and cooling beyond standard quantum limits.

Findings

Mechanical squeezing beyond 3 dB standard quantum limit.

Ground-state cooling achievable with appropriate nonlinearities.

Nonlinear gain medium enhances cooling and squeezing performance.

Abstract

In this paper, we study theoretically a hybrid optomechanical system consisting of a degenerate optical parametric amplifier inside a driven optical cavity with a moving end mirror which is modeled as a stiffening Duffing-like anharmonic quantum mechanical oscillator. By providing analytical expressions for the critical values of the system parameters corresponding to the emergence of the multistability behavior in the steady-state response of the system, we show that the stiffening mechanical Duffing anharmonicity reduces the width of the multistability region while the optical parametric nonlinearity can be exploited to drive the system toward the multistability region. We also show that for appropriate values of the mechanical anharmonicity strength the steady-state mechanical squeezing and the ground-state cooling of the mechanical resonator can be achieved. Moreover, we find that the presence of the nonlinear gain medium can lead to the improvement of the mechanical anharmonicity-induced cooling of the mechanical motion, as well as to the mechanical squeezing beyond the standard quantum limit of 3 dB.