Quantum phase transitions of three-level atoms interacting with a one-mode electromagnetic field

TL;DR

This paper investigates quantum phase transitions in a system of three-level atoms interacting with a single electromagnetic mode, analyzing different configurations and identifying the nature of phase transitions through energy surface methods.

Contribution

It applies the energy surface method to three-level atom systems in various configurations, providing estimations of ground-state properties and phase transition characteristics.

Findings

First and second-order phase transitions identified

V configuration exhibits only second-order phase transitions

Results agree with exact solutions

Abstract

We apply the energy surface method to study a system of Na three-level atoms interacting with a one-mode radiation field in the \Xi, \Lambda and V configurations. We obtain an estimation of the ground-state energy, the expectation value of the total number of excitations, and the separatrix of the model in the interaction parameter space, and compare the results with the exact solutions. We have first and second-order phase transitions, except for the V configuration which only presents second-order phase-transitions.