Geometric quantum discord of a Jaynes-Cummings atom and an isolated atom

TL;DR

This paper analyzes the geometric quantum discord in a system comprising a Jaynes-Cummings atom, a cavity, and an isolated atom, revealing its dynamic behavior and analytical expressions.

Contribution

It provides analytical formulas for geometric quantum discord in a complex atom-cavity system and explores its oscillatory behavior under different initial conditions.

Findings

Quantum discord can be non-zero even when entanglement vanishes.

The total system's quantum discord oscillates periodically with specific frequencies.

Initial state conditions influence the oscillation frequencies of quantum discord.

Abstract

We studied the geometric quantum discord of a quantum system consisted of a Jaynes- Cummings atom, a cavity and an isolated atom. The analytical expressions of the geometric quantum discord for two atoms, every atom with cavity and the total system were obtained. We showed that the geometric quantum discord is not always zero when entanglement fall in death for two-atom subsystem; the geometric measurement of quantum discord of the total system developed periodically with a single frequency if the initial state of two atoms was not entangled, otherwise, it oscillates with two or four frequencies according to the cavity is initially empty or not, respectively.