SU(2) symmetry in a Hubbard model with spin-orbit coupling  

作　　者：ZHANG XiZheng JIN Liang SONG Zhi 

机构地区：[1]College of Physics and Materials Science,Tianjin Normal University [2]School of Physics,Nankai University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2014年第11期2086-2091,共6页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11374163);the National Basic Research Program of China(Grant No.2012CB921900)

摘　　要：We study the underlying symmetry in a spin-orbit coupled tight-binding model with Hubbard interaction.It is shown that,in the absence of the on-site interaction,the system possesses the SU(2)symmetry arising from the time reversal symmetry.The influence of the on-site interaction on the symmetry depends on the topology of the networks:The SU(2)symmetry is shown to be the spin rotation symmetry of a simply-connected lattice even in the presence of the Hubbard interaction.On the contrary,the on-site interaction breaks the SU(2)symmetry of a multi-connected lattice.This fact indicates that a discrete spin-orbit coupled system has exclusive features from its counterpart in a continuous system.The obtained rigorous result is illustrated by a simple ring system.We study the underlying symmetry in a spin-orbit coupled tight-binding model with Hubbard interaction.It is shown that,in the absence of the on-site interaction,the system possesses the SU（2）symmetry arising from the time reversal symmetry.The influence of the on-site interaction on the symmetry depends on the topology of the networks：The SU（2）symmetry is shown to be the spin rotation symmetry of a simply-connected lattice even in the presence of the Hubbard interaction.On the contrary,the on-site interaction breaks the SU（2）symmetry of a multi-connected lattice.This fact indicates that a discrete spin-orbit coupled system has exclusive features from its counterpart in a continuous system.The obtained rigorous result is illustrated by a simple ring system.

关 键 词：symmetry Hubbard orbit connected reversal rigorous contrary counterpart rotation tight 

分 类 号：O469[理学—凝聚态物理]