Eur. Phys. J. D 58, 379-384 (2010)
https://doi.org/10.1140/epjd/e2010-00126-4

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

¹ Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
² ERATO, JST, Macroscopic Quantum Control Project, Hongo, Bunkyo-Ku, 113-8656, Tokyo, Japan

Corresponding authors: ^a liyonghn@gmail.com - ^b zwang@hkucc.hku.hk

Received: 11 November 2009
Revised: 1 April 2010
Published online: 12 May 2010

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 Δ-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.