拓展Bose-Hubbard模型的有限系统密度矩阵重整化群算法  

FS-DMRG for one-dimensional extended Bose-Hubbard model

作　　者：周伟[1] 周文慧[1] 谢明轩[1] 

机构地区：[1]中南大学物理科学与技术学院,湖南长沙410083

出　　处：《长沙理工大学学报（自然科学版）》2015年第2期78-82,共5页Journal of Changsha University of Science and Technology:Natural Science

基　　金：国家自然科学基金资助项目(11274390)

摘　　要：运用有限系统密度矩阵重整化群算法(FS-DMRG),研究拓展Bose-Hubbard模型(即在标准BoseHubbard模型的基础上加入最近邻格点间的粒子相互排斥作用V)发生相变的特征。通过计算系统的局域粒子数密度、单粒子能隙以及压缩系数,分析了系统在不同状态下的特征,得到了不同于标准Bose-Hubbard模型的新量子态——Charge Density Wave(CDW)态。通过分析产生特殊粒子分布方式的原因及其物理性质,得出了发生相变的临界条件。The zero-temperature phase transition of the one-dimensional Bose-Hubbard mod- el with nearest-neighbor interaction is investigated using the finite size density matrix tenor- realization group method（FS-DMRG）. By calculating the energy and associated eigenstate of the system＇s ground state with certain parameters, the local density, chemical potential and the compressibility are obtained, from which different phases, i.e. superfluid（SF）, Mott in- sulator（MI） and the charge density wave（CDW）, can be characterized. In addition, from the phase diagram, the critical conditions of transitions gre gotten from MI to SF and CDW to SF. All these results obtained are more accurate than those of previous researches.

关 键 词：拓展Bose-Hubbard模型 FS-DMRG算法 CDW态 

分 类 号：O413[理学—理论物理]