一维超晶格中超冷费米气体的量子相变  

Quantum Phase Transitions of Fermionic Atoms Trapped in a One-dimensional Optical Superlattice

作　　者：张旭华[1] 梁军军[1] 

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）》2015年第1期111-114,共4页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金(11005071)

摘　　要：用密度重整化群(DMRG)方法研究一维超晶格中超冷吸引相互作用费米气体的量子相变。研究发现:在引入超晶格势后,FFLO态的范围被缩小,同时BCS态的范围被扩大;在填充率为1时,前述效应最为明显。研究还发现随着超晶格势(D)作用的不断增强,必须加大Zeeman场的强度才能破坏简并引起极化,从而产生FFLO态。We study the ground-state properties of fermionic atoms confined in a one-dimensional optical superlattice by using the DMRG method.We find that the local potential enhances the BCS superfluid phase while suppresses the FFLO phase.At the filling factor n=1,with the increasing of local potential D,the BCS superfluid phase appears in the large Zeeman field region while the FFLO phase appears in the small Zeeman field region.We also find that,with the increasing of local potential D,one must increase the intensity of Zeeman field to destroy degeneracy and generate to polarization in order to reach the FFLO phase.

关 键 词：Fermi-Hubbard模型 密度重整化群 FFLO BCS Zeeman场 

分 类 号：O469[理学—凝聚态物理]