Frozen Gaussian quantum discord in photonic crystal cavity array system

TL;DR

This paper demonstrates that Gaussian quantum discord in a continuous-variable bipartite system can be preserved in a steady state under non-Markovian dynamics by engineering reservoir structures, with potential realization in photonic crystal cavity arrays.

Contribution

It reveals a method to freeze quantum discord in steady state through reservoir engineering in a photonic crystal cavity system.

Findings

Quantum discord can be frozen in steady state under non-Markovian dynamics.

Reservoir structure engineering enables preservation of quantum correlations.

Proposed realization in photonic crystal cavity arrays.

Abstract

Protecting quantum correlation from decoherence is one of the crucial issues in quantum information processing. It has been commonly recognized that any initial quantum correlation of a composite system diminishes asymptotically or abruptly to zero under local Markovian decoherence. Here we show that, contrary to this recognition, a noticeable Gaussian quantum discord of a continuous-variable bipartite system can be frozen in the steady state in the non-Markovian dynamics if each of the subsystems forms a localized mode with its local reservoir. The condition for this frozen quantum discord can be reached by appropriately engineering the structure of the reservoirs. The possible realization of our results in a coupled cavity array system formed by a photonic crystal is proposed.