Entanglement dynamics in a model tripartite quantum system

TL;DR

This paper explores how initial states, detuning, nonlinearities, and coupling types influence entanglement and optical phenomena like EIT in a tripartite atom-field system, revealing sensitive entanglement dynamics and collapse-revival behaviors.

Contribution

It provides a simplified model analyzing the impact of various parameters on entanglement and optical effects in tripartite atom-field interactions, highlighting the role of intensity-dependent couplings.

Findings

Entanglement dynamics are highly sensitive to atom-field coupling strengths.

Collapse and revival phenomena are observed in atomic entropy.

Initial states and nonlinearities significantly affect EIT and entanglement behavior.

Abstract

A system comprising a $\Lambda$-type or V-type atom interacting with two radiation fields exhibits, during its dynamical evolution, interesting optical phenomena such as electromagnetically-induced transparency (EIT) and a variety of nonclassical effects. Signatures of the latter are seen in the entanglement dynamics of the atomic subsystem and in appropriate field observables. Some of these effects have been experimentally detected, and have even been used to change the nonlinear optical properties of certain atomic media. It is therefore useful to investigate the roles played by specific initial states of the radiation fields, detuning parameters, field nonlinearities and the nature of field-atom couplings on EIT and on the entanglement between subsystems. We investigate these aspects in the framework of a simple model that captures the salient features of such tripartite entangled systems. Entanglement dynamics is shown to be very sensitive to the intensity-dependent atom-field couplings. Unexpected interesting features pertaining to the collapses and revivals of the atomic subsystem von Neumann entropy appear. These features could, in principle, be useful in enabling entanglement.