Remote transfer of Gaussian quantum discord

TL;DR

This paper presents a scheme for remotely transferring Gaussian quantum discord, enabling quantum correlation between optical modes without direct interaction, with potential applications in quantum networks.

Contribution

It introduces a novel scheme for remote transfer of Gaussian quantum discord using ancillary states, enhancing quantum correlations beyond initial levels.

Findings

Output Gaussian quantum discord can surpass initial discord with optimal parameters.

Quantum discord of asymmetric states can be higher than symmetric states.

The scheme enables quantum correlation transfer without direct interaction.

Abstract

Quantum discord quantifies quantum correlation between quantum systems, which has potential application in quantum information processing. In this paper, we propose a scheme realizing the remote transfer of Gaussian quantum discord, in which another quantum discordant state or an Einstein-Podolsky-Rosen entangled state serves as ancillary state. The calculation shows that two independent optical modes that without direct interaction become quantum correlated after the transfer. The output Gaussian quantum discord can be higher than the initial Gaussian quantum discord when optimal gain of the classical channel and the ancillary state are chosen. The physical reason for this result comes from the fact that the quantum discord of an asymmetric Gaussian quantum discordant state can be higher than that of a symmetric one. The presented scheme has potential application in quantum information network.