Effect of Interatomic Separation on Entanglement Dynamics in a Two-Atom Two-Mode Model

TL;DR

This paper investigates how the distance between two atoms affects their entanglement dynamics when interacting with a two-mode electromagnetic field, revealing significant differences based on symmetry and separation.

Contribution

It provides a detailed analysis of entanglement evolution for various atomic separations, highlighting the impact of symmetry on entanglement phenomena in two-atom two-mode systems.

Findings

Entanglement behaviors vary significantly with atomic separation.

Symmetric couplings lead to distinct entanglement features.

General distances exhibit complex entanglement dynamics unlike special symmetric cases.

Abstract

We analyze the time evolution of quantum entanglement in a model consisting of two two-level atoms interacting with a two-mode electromagnetic field for a variety of initial states and interatomic separations. We study two specific atomic separations which give rise to symmetric atom-field couplings. For general atomic distances we consider a subset of initial states analytically, and then treat the more general situation numerically. We examine a variety of qualitative features such as entanglement sudden death, dynamical generation, protection, and transfer between subsystems. Our analysis shows a stark contrast in features of entanglement between the two special coupling schemes often considered; further, these features are uncharacteristic of those arising for general distances, due to the high degree of symmetry present in the special cases. The variety of behaviors in these two-mode cases suggest the importance of considering atomic separation carefully for any model where two atoms interact with a common field.