光学腔辅助动力学晶格中的两组分玻色子  

Two-component Bosons inside a Cavity-assisted Dynamical Optical Lattice

作　　者：张雅丽[1] 樊景涛 贾锁堂[1] ZHANG Ya-li;FAN Jing-tao;JIA Suo-tang(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Laser Spectroscopy,Shanxi University,Taiyuan,030006,China)

机构地区：[1]山西大学激光光谱研究所量子光学与光量子器件国家重点实验室,山西太原030006

出　　处：《量子光学学报》2024年第4期46-59,共14页Journal of Quantum Optics

基　　金：国家自然科学基金(12174233);“1331工程”提质增效建设计划(晋教科[2021]4号)。

摘　　要：本文研究一种由光学腔辅助的两组分晶格玻色子系统。在真空环境下,该玻色气体的两个组分具有完全不同的局域特征,而腔光子会诱导两个组分间的隧穿。利用变分方法和自洽平均场方法,我们系统分析了体系的基态性质,得到了系统在不同参数空间下的相图。相图展现出了丰富的量子相,包括莫特绝缘体相、超流相和超辐射超流相等。我们发现在腔光子的辅助下,巡游组分的玻色子会诱导局域组分的玻色子发生超流转变。特别地,在特定参数区间内,组分间相互作用会驱动由莫特绝缘体到超辐射超流的反常量子相变。文章最后我们给出了可行的实验方案。我们的工作丰富了玻色-哈伯德模型的相关物理,并为利用光学腔中的超冷原子模拟凝聚态现象提供了有益的思路。As a basic model to describe strongly correlated Bose gases in lattice potential,the Bose-Hubbard model has been a hot topic in physics since it was proposed.The extension of the Bose-Hubbard model to a two-component coupled gas is straightforward and interesting.In particular,when the two components of bose gas experience completely different lattice potentials and interactions,the system will show very different properties from that of a single-component gas.Similarly,the interactions between itinerant and local particles in heavy fermion systems have been extensively studied,and a wealth of quantum phenomena have been discovered.So,what kind of novel phenomena will be produced by itinerant particles and local particles in the bosonic quantum system?In this paper,we consider the ground state properties of a two-component lattice boson system assisted by an optical cavity.In the vacuum environment,we assume that the two components of the bose gas are trapped in an optical lattice dependent on the spin internal states,where one component is completely local and the other is itinerant,and cavity photons can induce tunneling between the two components.In this work, variational method and self-consistent mean field approach are used to study the ground state properties of the system.These two methods have their own applicable scope and analytical advantages. In the case of the hard-core limit, the Hilbertspace of the system is greatly reduced, and the analytical expression of the energy density of the system can be easily obtained byusing the variational wave function, and the ground state properties of the system can be obtained by solving each parameter ofthe system through analytic calculation. However, in any real experimental system, the interactions between atoms are alwaysfinite, and the Hilbert space of the system is no longer restricted. In principle, the self-consistent mean field approach can dealwith systems with arbitrary finite interaction strength. Utilizing the mean field decoupling approximation, we

关 键 词：量子相变 冷原子 光学腔 光晶格 

分 类 号：O562[理学—原子与分子物理]