双光子过程耗散耦合腔阵列中的量子相变  

Quantum phase transition in arrays of dissipative cavities with two-photon process

作　　者：熊芳[1] 冯晓强[1] 谭磊[1] 

机构地区：[1]兰州大学理论物理研究所,兰州730000

出　　处：《物理学报》2016年第4期103-108,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11274148)资助的课题~~

摘　　要：基于准玻色方法,利用平均场理论解析求解了环境作用下双光子过程耦合腔阵列体系的哈密顿量,得到了体系序参量的解析表达式,并讨论了耗散对体系超(流-M)ott绝缘相变的影响.研究结果表明:双光子共振′情况下系统重铸相干的腔间耦合率临界值为ZJ/β=(ZJ/β)'_c=0.34;双光子相互作用过程比单光子过程具有更大的耗散率,系统维持长程相干状态的时间更短,而实现重铸相干的腔间耦合率的临界值更大.In this paper, we employ a new kind of quasi-boson approach and the mean field theory to study analytically the Hamiltonian of an array of cavities with a three-level atom embedded in each cavity in the process of two-photon resonant transition under the influence of a bosonic bath. The superfluid order parameter of the system is obtained analytically and then analyzed numerically to investigate the effects of dissipation on the quantum phase transition from the superfluid to the Mort-insulator phase. It is shown that when the two-photon resonance is achieved one can have the superfluid phase at ZJ/β=（ZJ/β）＇_c=0.34 in the related ideal case. Furthermore, the system while in the two-photon resonant process has a larger dissipation rate as compared with that in the one-photon resonant process, thus leading to the suppression of the long-range coherence time and enhancement of the critical hopping rate for restoring coherence.

关 键 词：双光子过程 耦合腔阵列 超流-Mott绝缘相变 准玻色子 

分 类 号：O431.2[机械工程—光学工程]