Gaussian geometric discord, entanglement and EPR-steering of two rotational mirrors in a double Laguerre-Gaussian cavity optomechanics in the presence of YIG sphere

TL;DR

This paper proposes a theoretical scheme to analyze quantum correlations such as steering, entanglement, and geometric discord between two rotating mirrors in a double-Laguerre-Gaussian cavity with a YIG sphere, highlighting parameter effects and experimental feasibility.

Contribution

It introduces a novel theoretical model for stationary Gaussian quantum correlations in a double-LG cavity with a YIG sphere, exploring parameter influences and robustness against thermal noise.

Findings

Stationary entanglement is achievable and optimal with specific parameters.

Entanglement is fragile under thermal effects, but Gaussian discord shows resilience.

Both one-way and two-way steering can be realized under accessible experimental conditions.

Abstract

EPR steering is a nonclassical correlation that exhibits properties intermediate to entanglement and Bell nonlocality, providing a valuable resource for quantum communication and computation. In this work, we propose a theoretical scheme to investigate stationary gaussian quantum steering, entanglement and Gaussian geometric discord of two spatially separated rotating mirrors (Rms) in a double-Laguerre-Gaussian cavity (DLGC). Each cavity is derived by Laguerre-Gaussian (LG) beam, and a Yttrium Iron Garnet sphere (YIG) is injected in the intersection of the two cavities. We employ Gaussian quantum steering to characterize the steerability between the Rms. The logarithmic negativity measure is used to quantify the amount of entanglement. We quantify all nonclassical correlations between the Rms by harnessing the Gaussian geometric discord (GGD) measure. Our results indicate that various physical parameters, including the temperature, detuning of the magnon mode frequency, orbital angular momentum (OAM) of the LG cavity modes, the coupling between magnon and cavity mode, the mass of the Rms, each play distinct roles in establishing ${\rm Rm_1-Rm_2}$ entanglement. We characterize the entanglement of the two Rms under ambient temperature (300 K). Stationary entanglement is optimal by adjusting the values of Rms frequency and photon-magnon coupling. We show that the stationary entanglement is fragile under thermal effects. Besides, the GGD demonstrates strong resilience to thermal noise, and this can be further enhanced by increasing the mass of the Rms. Under experimentally accessible parameters and with adjusted ratio between the angular frequencies, we achieve both one-way and two-way steering. Finally, we address the feasibility of our proposal based on the present experiments.