Creation of bipartite steering correlations by a fast damped auxiliary mode

TL;DR

This paper demonstrates how fast dissipation of an auxiliary mode in a three-mode system can generate directional quantum steering correlations between the remaining modes, with analytical results and robustness analysis.

Contribution

It introduces a method to create quantum steering via fast dissipation in a three-mode system, providing explicit analytical steering parameters and exploring conditions for one- and two-way steering.

Findings

Steering correlations can be generated by fast dissipation of an auxiliary mode.

Two coupled modes with the same damping rates can be entangled but not steer.

Steering occurs when the variance of the steering mode exceeds that of the steered mode.

Abstract

We consider a three-mode system and show how steering correlations can be created between two modes of the system using the fast dissipation of the third mode. These correlations result in a directional form of entanglement, called quantum or EPR steering. We illustrate this on examples of the interactions among damped radiation modes in an optomechanical three-mode system. By assuming that one of the modes undergoes fast dissipation, we show that the coupling of that mode to one or two other modes of the system may result in one- or two-way quantum steering. Explicit analytical results are given for the steering parameters. We find that two modes coupled by the parametric-type interaction and damped with the same rates can be entangled but cannot exhibit quantum steering. When, in addition, one of the modes is coupled to a fast damped mode, steering correlations are created and the modes then exhibit one-way steering. The creation of the steering correlations is interpreted in the context of the variances of the quadrature components of the modes that the steering correlations result from an asymmetry in the variances of the quadrature components of the modes induced by the auxiliary mode. It is found that the fluctuations act directionally that quantum steering may occur only when the variance of the steering mode is larger that the variance of the steered mode. The scheme is shown to be quite robust against the thermal excitation of the modes if the fluctuations of the steering mode are larger than the fluctuations of the steered mode.