Achieving steady-state entanglement of remote micromechanical oscillators by cascaded cavity coupling

TL;DR

This paper presents a method to generate steady-state entanglement among remote micromechanical oscillators using cascaded cavity coupling, controllable squeezing, and cavity dissipation, without needing nonclassical light or measurements.

Contribution

It introduces a novel scheme for steady-state entanglement of remote mechanical oscillators via cascaded cavities, applicable to multiple oscillators, and robust against thermal noise.

Findings

Steady-state two-mode squeezing of mechanical oscillators achieved.

Multipartite entanglement can be established among multiple oscillators.

The scheme is feasible with current experimental technology.

Abstract

In this paper, we propose a scheme for generating steady-state entanglement of remote micromechanical oscillators in unidirectionally-coupled cavities. For the system of two mechanical oscillators, we show that when two cavity modes in each cavity are driven at red- and blue-detuned sidebands, respectively, a stationary two-mode squeezed vacuum state of the two mechanical oscillators can be generated with the help of the cavity dissipation. The degree of squeezing is controllable by adjusting the relative strength of the pump lasers. Our calculations also show that the achieved mechanical entanglement is robust against thermal fluctuations of phononic environments. For the case of multiple mechanical oscillators, we find that the steady-state genuine multipartite entanglement can also be built up among the remote mechanical oscillators by the cavity dissipation. The present scheme does not require nonclassical light input or conditional quantum measurements, and it can be realized with current experimental technology.