自旋轨道耦合对一维光学晶格中吸引性费米原子气体基态性质的影响  

Effect of Spin-orbit Coupling on the Ground State Properties of Attractive Fermi Gas in One-dimensional Optical Lattice

作　　者：丁瑜 梁军军[1] DING Yu;LIANG Junjun(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1552-1557,共6页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金(11875181)。

摘　　要：文章利用矩阵乘积态(MPS)方法研究了吸引性超冷费米原子气体在自旋轨道耦合(SOC)驱动下的基态性质。一般Zeeman场会使系统处于Fulde-Ferrell-Larkin-Ovchinnikov(FFLO)超流态,考虑SOC后我们发现SOC会使FFLO超流态区间变窄。配对质心动量Q随Zeeman场增强而减小,与极化P呈现出线性关系Q=(1-P)π,并且不受SOC影响。通过数值分析准粒子能谱、纠缠熵和纠缠谱,发现在SOC和吸引相互作用下,FFLO超流态是拓扑非平庸的。In this work,we employ the matrix product state(MPS)to investigate the ground-state properties of spin-orbit coupling(SOC)attracting ultra-cold Fermi gas.The Zeeman field may give rise to Fulde-Ferferrell-Larkin-Ovchinnikov(FFLO)state.The center-of-mass momentum(Q)decreases with Zeeman field enhancement,exhibiting a linear relationship Q=(1-P)π.We show that SOC shrinks the FFLO superfluid region at Q independent manner.Through a numerical analysis of the quasi-particle energy spectrum,entanglement entropy and entanglement spectrum,we find that the FFLO state is nontrivial topological in the presence of SOC and attractive interactions.

关 键 词：超冷费米气体 自旋轨道耦合 Fulde-Ferrell-Larkin-Ovchinnikov 拓扑 

分 类 号：O469[理学—凝聚态物理]