Pure and Mixed State Entanglement Dynamics in Tavis-Cummings Model with Squeezed Coherent Thermal States

TL;DR

This paper studies how entanglement between two atoms and a cavity field evolves under noise, considering pure and mixed initial states, with findings on how thermal noise and squeezing affect entanglement dynamics.

Contribution

It provides a detailed analysis of entanglement dynamics in the Tavis-Cummings model with squeezed thermal states, highlighting the effects of noise, nonlinearities, and initial state purity.

Findings

Thermal photons suppress entanglement and cause sudden death.

Squeezing mitigates thermal noise effects on entanglement.

Entanglement behavior varies significantly between Bell and Werner initial states.

Abstract

We investigate the entanglement dynamics of two atoms interacting with a single-mode cavity field within the Tavis-Cummings model in the presence of noise. The atoms are initially prepared in either pure Bell states or mixed Werner states, allowing a direct comparison of pure- and mixed-state entanglement. The cavity field is described by generalized single-mode squeezed coherent thermal states, incorporating both thermal and quantum noise effects. Atom-atom and atom-field entanglement are quantified using concurrence and negativity, respectively. We analyze entanglement sudden death and revival, and examine how Ising-type coupling, dipole-dipole interaction, Kerr nonlinearity, and detuning modify the entanglement dynamics. Our results show that thermal photons generally suppress entanglement and enhance sudden death, while squeezing counteracts these effects. The influence of nonlinearities and interatomic interactions depends sensitively on the purity of the initial atomic state, leading to qualitatively different behaviors for Bell and Werner states.