Robustness of quantum correlations against decoherence

TL;DR

This paper investigates how quantum correlations in a two-qubit system evolve under decoherence, revealing that their robustness can be improved through local unitary operations, with different measures providing varied insights.

Contribution

It provides an exact analysis of nonclassical correlations dynamics under spontaneous emission and shows how local unitaries enhance their robustness.

Findings

Different measures yield varied qualitative characterizations.

Local unitaries can significantly enhance correlation robustness.

Explicit behavior of correlation measures for various states.

Abstract

We study dynamics of nonclassical correlations by exactly solving a model consisting of two atomic qubits with spontaneous emission. We find that the nonclassical correlations defined by different measures give different qualitative characterizations of those correlations. The relative behaviors of those correlation measures are presented explicitly for various quantum states in the two-qubit atomic system. In particular, we find that the robustness of quantum correlations can be greatly enhanced by performing appropriate local unitary operations on the initial state of the system.