Phase diagram of the Fermi-Hubbard model with spin-dependent external potentials: A DMRG study  

作　　者：魏兴波 孟烨铭 吴哲明 高先龙 

机构地区：[1]Department of Physics, Zhejiang Normal University

出　　处：《Chinese Physics B》2015年第11期393-397,共5页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11374266 and 11174253);the Program for New Century Excellent Talents in University,China

摘　　要：We investigate a one-dimensional two-component system in an optical lattice of attractive interactions under a spin- dependent external potential. Based on the density-matrix renormalization group methods, we obtain its phase diagram as a function of the external potential imbalance and the strength of the attractive interaction through the analysis on the density profiles and the momentum pair correlation functions. We find that there are three different phases in the system, a coexisted fully polarized and Fulde-Ferrell-Larkin-Ovchinnikov （FFLO） phase, a normal polarized phase, and a Bardeen- Cooper-Schrieffer （BCS） phase. Different from the systems of spin-independent external potential, where the FFLO phase is normally favored by the attractive interactions, in the present situation, the FFLO phases are easily destroyed by the attractive interactions, leading to the normal polarized or the BCS phase.We investigate a one-dimensional two-component system in an optical lattice of attractive interactions under a spin- dependent external potential. Based on the density-matrix renormalization group methods, we obtain its phase diagram as a function of the external potential imbalance and the strength of the attractive interaction through the analysis on the density profiles and the momentum pair correlation functions. We find that there are three different phases in the system, a coexisted fully polarized and Fulde-Ferrell-Larkin-Ovchinnikov （FFLO） phase, a normal polarized phase, and a Bardeen- Cooper-Schrieffer （BCS） phase. Different from the systems of spin-independent external potential, where the FFLO phase is normally favored by the attractive interactions, in the present situation, the FFLO phases are easily destroyed by the attractive interactions, leading to the normal polarized or the BCS phase.

关 键 词：Fermi-Hubbard model spin-dependent potential Fulde-Ferrell-Larkin-Ovchinnikov （FFLO）phase 

分 类 号：O641.1[理学—物理化学]