Universality of stationary entanglement in an optomechanical system driven by non-Markovian noise and squeezed light

TL;DR

This paper explores how environmental noise affects stationary entanglement in optomechanical systems driven by squeezed light, revealing a universal transition point beyond which entanglement is lost, regardless of system parameters.

Contribution

It demonstrates a universal entangling-disentangling transition in optomechanical systems under non-Markovian noise, independent of coupling strength or squeezing factor.

Findings

Entanglement is destroyed beyond a noise-dependent threshold.

Frequency-dependent squeezing cannot generate entanglement if the system is initially separable.

A universal transition point for entanglement loss was identified.

Abstract

Optomechanical systems subjected to environmental noise give rise to rich physical phenomena. We investigate entanglement between a mechanical oscillator and the reflected coherent optical field in a general, not necessarily Markovian environment. For the input optical field, we consider stationary Gaussian states and frequency dependent squeezing. We demonstrate that for a coherent laser drive, either unsqueezed or squeezed in a frequency-independent manner, optomechanical entanglement is destroyed after a threshold that depends only on the environmental noises -- independent of the coherent coupling between the oscillator and the optical field, or the squeeze factor. In this way, we have found a universal entangling-disentangling transition. We also show that for a configuration in which the oscillator and the reflected field are separable, entanglement cannot be generated by incorporating frequency-dependent squeezing in the optical field.