一维光晶格中排斥费米气体的超流特性  

Superfluidity of Repulsive Fermi Gas in a One-dimensional Optical Lattice

作　　者：刘娇 李志坚[1] LIU Jiao;LI Zhijian(Institute of Theoretical Physics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学理论物理研究所,山西太原030006

出　　处：《山西大学学报（自然科学版）》2022年第6期1547-1551,共5页Journal of Shanxi University(Natural Science Edition)

摘　　要：用密度矩阵重整化群方法(DMRG)研究了自旋轨道耦合与谐振外势同时存在时的一维光晶格的排斥费米原子气体的基态性质。研究发现,在一维光晶格中的占据数小于半填充情况下,当只考虑谐振外势时,系统的排斥相互作用超过某一临界值时,系统存在费米超流。当同时考虑谐振外势和自旋轨道耦合时,发现当系统处于金属态时,自旋轨道耦合增强了金属性;当系统处于Mott绝缘态时,自旋轨道耦合减弱了绝缘性且存在超流性。最后分析了在自旋轨道耦合作用下系统的填充数对配对的影响,谐振外势强度的变化与自旋轨道耦合对束缚态的影响。The ground state properties in a fermi gas of atoms with repulsive interaction loaded on a one-dimensional optical lattice with spin-orbit coupling and harmonic trap potential are studied by using density-matrix renormalization group(DMRG)method.If only the harmonic trap potential is considered,we find that,when the strength of the repulsive interaction exceeds a critical value,fermion superfluidity appears.While if the harmonic trap potential and the spin-orbit coupling are considered simultaneously,the spin-orbit coupling enhances metallicity when the system is in metallic state,but weakens the insulativity and leads to superfluidity when the system is in Mott insulating state.Finally,we investigate the effect of the filling number on the pairing in the spin-orbit coupling and discuss the influence of the variation of harmonic trap potential strength and spin-orbit coupling on the bound state.

关 键 词：Feimi-Hubbard模型 密度矩阵重整化群 自旋轨道耦合 束缚能 

分 类 号：O436[机械工程—光学工程]