First-Order Quantum Phase Transition for Dicke Model Induced by Atom-Atom Interaction

• 来源期刊: 理论物理通讯（英文版）
• 年，卷（期）: 2017,（5）
• 页码范围: 511-519
• 页数: 9页
• 语种: 英文
• DOI: 10.1088/0253-6102/67/5/511

摘要

In this article,we use the spin coherent state transformation and the ground state variational method to theoretically calculate the ground function.In order to consider the influence of the atom-atom interaction on the extended Dicke model's ground state properties,the mean photon number,the scaled atomic population and the average ground energy are displayed.Using the self-consistent field theory to solve the atom-atom interaction,we discover the system undergoes a first-order quantum phase transition from the normal phase to the superradiant phase,but a famous Dicke-type second-order quantum phase transition without the atom-atom interaction.Meanwhile,the atom-atom interaction makes the phase transition point shift to the lower atom-photon collective coupling strength.