Extended JC-Dicke model for a two-component atomic BEC inside a cavity

TL;DR

This paper derives an extended JC-Dicke model for a two-component atomic BEC in a cavity, revealing a new phase transition influenced by the microwave field's sign change, and analyzes the ground-state energy and phase diagram.

Contribution

It introduces an extended JC-Dicke model for a multi-level BEC system and uncovers a novel phase transition driven by microwave field sign change.

Findings

Identification of a new phase transition related to microwave field sign change

Analysis of ground-state energy and phase diagram of the extended model

Demonstration of the model's applicability to two-component BEC systems

Abstract

We consider a trapped two-component atomic Bose-Einstein condensate (BEC), where each atom with three energy-levels is coupled to an optical cavity field and an external classical optical field as well as a microwave field to form the so-called $\Delta$-type configuration. After adiabatically eliminating the atomic excited state, an extended JC-Dicke model is derived under the rotating-wave approximation. The scaled ground-state energy and the phase diagram of this model Hamiltonian are investigated in the framework of mean-field approach. A new phase transition is revealed when the amplitude of microwave field changes its sign.