Non-Markovian effect on the quantum discord

TL;DR

This paper investigates how non-Markovian environments influence quantum discord dynamics, revealing that quantum discord does not undergo sudden death but only instantaneous disappearance, making it a more robust measure of quantum correlations than entanglement.

Contribution

The study provides an exact analysis of non-Markovian effects on quantum discord dynamics, highlighting differences from entanglement behavior and emphasizing quantum discord's robustness.

Findings

Quantum discord experiences only instantaneous disappearance, not sudden death.

Quantum discord is more resilient than entanglement in non-Markovian environments.

Exact solutions clarify the dynamics of quantum correlations under non-Markovian effects.

Abstract

We study the non-Markovian effect on the dynamics of the quantum discord by exactly solving a model consisting of two independent qubits subject to two zero-temperature non-Markovian reservoirs, respectively. Considering the two qubits initially prepared in Bell-like or extended Werner-like states, we show that there is no occurrence of the sudden death, but only instantaneous disappearance of the quantum discord at some time points, in comparison to the entanglement sudden death in the same range of the parameters of interest. It implies that the quantum discord is more useful than the entanglement to describe quantum correlation involved in quantum systems.