Steady-state entanglement activation in optomechanical cavities

TL;DR

This paper demonstrates a novel steady-state entanglement activation mechanism in optomechanical cavities, where quantum discord enables persistent entanglement despite noise, advancing quantum information processing capabilities.

Contribution

It introduces a discord-activated process that produces steady-state entanglement in optomechanical systems, a significant step beyond previous dynamic-only schemes.

Findings

Steady-state entanglement can be activated via quantum discord.

Quantum discord enhances robustness of entanglement against noise.

The mechanism is demonstrated in a realistic optomechanical cavity setup.

Abstract

Quantum discord, and a number of related indicators, are currently raising a relentless interest as a novel paradigm of non-classical correlations beyond entanglement. Beside merely fundamental aspects, various works have shown that discord is a valuable -- so far largely unexplored -- resource in quantum information processing. Along this line, quite a striking scheme is {entanglement activation}. An initial amount of discord between two disentangled parties of a multipartite system affects the dynamics so as to establish entanglement across a bipartition, which would not arise otherwise. To date, such a process was proven to be achievable only dynamically, i.e., with no guarantee of a stationary entanglement throughput in the presence of noise. Here, we discover a {\it discord-activated mechanism yielding steady-state entanglement} production in a realistic continuous-variable setup. This comprises two coupled optomechanical cavities, where the optical modes (OMs) communicate through a fiber. We first use a simplified model to highlight the creation of steady-state discord between the OMs. We show next that such discord improves the level of stationary optomechanical entanglement attainable in the system, making it more robust against temperature and thermal noise.