Control of two-atom entanglement with two thermal fields in coupled cavities

TL;DR

This paper investigates how to control entanglement between two atoms in coupled cavities with thermal fields by tuning system parameters, achieving maximally entangled states and understanding entanglement dynamics.

Contribution

It demonstrates control of atomic entanglement via hopping strength and detuning, including generation of maximally entangled states and entanglement freezing.

Findings

Maximally entangled states can be generated when atoms are off-resonant.

Entanglement shows periodic sudden birth and death.

Entanglement can be frozen with proper parameters.

Abstract

The dynamical evolution of a quantum system composed of two coupled cavities, each containing a two-level atom and a single-mode thermal field, is investigated under different conditions. The entanglement between the two atoms is controlled by the hopping strength and the detuning between the atomic transition and the cavities. We find that when the atomic transition is far off-resonant with both the eigenmodes of the coupled cavity system, the maximally entangled state for the two atoms can be generated with the initial state in which one atom is in the ground state and the other is in the excited state. When both the two atoms are initially in the excited state, the entanglement exhibits period sudden birth and death. By choosing appropriate parameter values, the initial maximal entanglement of the two atoms can be frozen. The relation between the concurrence and cooperative parameter is calculated.