Quantifying quantumness of correlations using Gaussian R\'enyi-2 entropy in optomechanical interfaces

TL;DR

This paper investigates quantum correlations in optomechanical systems using Gaussian Rénnyi-2 entropy, demonstrating creation, sensitivity to noise, and a freezing behavior of quantum discord under thermal effects.

Contribution

It introduces a novel analysis of quantum correlations in optomechanical interfaces using Gaussian Rénnyi-2 entropy, highlighting the robustness of quantum discord.

Findings

Entanglement and discord can be generated via quantum fluctuations transfer.

Mechanical entanglement is more sensitive to thermal noise than optical.

Quantum discord of separable states remains stable over a wide temperature range.

Abstract

Using the Gaussian R\'enyi-2 entropy, we analyse the behaviour of two different aspects of quantum correlations (entanglement and quantum discord) in two optomechanical subsystems (optical and mechanical). We work in the resolved sideband and weak coupling regimes. In experimentally accessible parameters, we show that it is possible to create entanglement and quantum discord in the considered subsystems by quantum fluctuations transfer from either light to light or light to matter. We find that both mechanical and optical entanglement are strongly sensitive to thermal noises. In particular, we find that the mechanical one is more affected by thermal effects than that optical. Finally, we reveal that under thermal noises, the discord associated with the entangled state decays aggressively, whereas the discord of the separable state (quantumness of correlations) exhibits a freezing behaviour, seeming to be captured over a wide range of temperature.