Quantum dynamics of an optomechanical system in the presence of Kerr-down conversion nonlinearity

TL;DR

This paper theoretically investigates how Kerr and down conversion nonlinearities influence the dynamics, squeezing, and entanglement in an optomechanical system, revealing enhanced squeezing but reduced mirror-field entanglement.

Contribution

It introduces a comprehensive analysis of combined Kerr and parametric gain effects on optomechanical systems, highlighting their impact on spectral features and quantum correlations.

Findings

Kerr and gain nonlinearities increase normal mode splitting.

Both nonlinearities enhance the squeezing of transmitted light.

Kerr medium reduces the entanglement between mechanical and optical modes.

Abstract

We study theoretically nonlinear effects arising from the presence of a Kerr-down conversion nonlinear crystal inside an optomechanical cavity. For this system we investigate the influences of the two nonlinearities, i.e., the Kerr nonlinearity and the parametric gain, on the dynamics of the oscillating mirror, the intensity and the squeezing spectra of the transmitted field, and the steady-state mirror-field entanglement. We show that in comparison with a bare optomechanical cavity, the combination of the cavity energy shift due to the Kerr nonlinearity and increase in the intracavity photon number due to the gain medium can increase the normal mode splitting in the displacement spectrum of the oscillating mirror and reduce its effective temperature. Our work demonstrates that both the Kerr nonlinearity and down conversion process increase the degree of squeezing in the transmitted field. Moreover, we find that in the system under consideration the degree of entanglement between the mechanical and optical modes decreases considerably because of the intracavity photon number reduction in the presence of the Kerr medium.