Sudden transition between classical and quantum decoherence in dissipative cavity QED and stationary quantum discord

TL;DR

This paper studies how quantum discord in a dissipative cavity QED system exhibits sudden transitions and can remain stable over time, with the stationary quantum discord influenced by initial states and system parameters.

Contribution

It reveals the conditions under which quantum discord remains unaffected by cavity dissipation and characterizes the sudden transition phenomenon in this system.

Findings

Quantum discord persists over finite times despite cavity dissipation.

Stationary quantum discord can form as time approaches infinity.

Quantum discord can be unaffected by dissipation with proper parameter choices.

Abstract

We investigate the phenomenon of sudden transition between classical and quantum decoherence in the study of quantum discord for a dissipative cavity QED system, which consists of two noninteracting two-level atoms, each trapped in a dissipative cavity. It is found that the quantum discord between two atoms, which are prepared initially in the X-type quantum states, is not destroyed by the dissipation of the cavities for a finite time interval and the stationary quantum discord can arise in the interaction of atoms with cavities as the time approach to infinite. The transition time is sensitive to the initial state parameter of the two atoms and the mean photon number of the coherent field. Interestingly, the quantum discord between the two atoms is completely unaffected by the dissipation of the cavities if we choose the suitable value of the ratio, which depends on the decay rate of two cavities and the atom-field coupling constant.