Quantum discord dynamics of two qubits in the single-mode cavities

TL;DR

This paper investigates the dynamics of quantum discord and entanglement between two qubits in different cavity configurations, revealing distinct behaviors and stabilization effects influenced by initial states and detunings.

Contribution

It provides a comparative analysis of quantum discord and entanglement dynamics in independent and common cavities, highlighting the effects of initial states and detunings.

Findings

Quantum discord vanishes only at discrete moments in independent cavities.

Quantum discord never vanishes in the common cavity.

Detunings stabilize quantum discord regardless of cavity configuration.

Abstract

The dynamics of the quantum discord for two identical qubits in both two independent single-mode cavities and a common single-mode cavity are discussed. For the initial Bell state with correlated spins, while the entanglement sudden death can occur, the quantum discord vanishes only at discrete moments in the independent cavities and never vanishes in the common cavity. Interestingly, quantum discord and entanglement show opposite behaviors in the common cavity, unlike in the independent cavities. For the initial Bell state with anti-correlated spins, quantum discord and entanglement behave in the same way for both independent cavities and a common cavity. It is found that the detunnings always stabilize the quantum discord.