Quantum discord of mixed states under noisy channels in the curved spacetime

TL;DR

This paper investigates how quantum discord in two-qubit mixed states behaves near a Schwarzschild black hole under various noisy channels, revealing degradation patterns and symmetry properties.

Contribution

It introduces analytical relationships for quantum discord in curved spacetime under different noise channels, highlighting their similar behaviors and symmetry features.

Findings

Quantum discord degrades with increasing Hawking acceleration.

Sudden death of discord does not occur under studied channels.

Discords show symmetric behavior in bit flip and phase flip channels.

Abstract

We focus our attention on two-qubit mixed states as initial states, and apply the geometric measure of quantum discord to investigate quantum discord properties in the background of a Schwarzschild black hole under phase damping, phase flip and bit flip channels, respectively. Several analytical complementary relationships based on quantum discords for bipartite subsystems are proposed. For the three channel noises, the behaviors of discords are similar, the accessible discords always degrade as the Hawking acceleration rising, but sudden death never occurs, while the inaccessible discords increase from zero monotonically. Interestingly, in the case of the bit flip channel and phase flip channel, the discords perform symmetrically with the decay probability rising.