半满Hubbard模型的新处理方法  

A new treatment to the half-filled Hubbard model

作　　者：王齐放[1] 周青春[1] 

机构地区：[1]华东船舶工业学院数理系,江苏镇江212003

出　　处：《大学物理》2004年第7期8-9,15,共3页College Physics

摘　　要：从标准Hubbard模型出发,对半满狭带强关联系统,在讨论自旋为σ的电子运动时,忽略自旋为-σ的电子在格点间的跳跃,得到不对称哈密顿量,并运用平均场近似求得相应准粒子谱.在绝对零度时,与Green函数近似解作了比较;在有限温度时,讨论了从绝缘体到金属相变的可能.Starting from the standard Hubbard model, an asymmetric Hamiltonian for the half-filled strongly correlated system by ignoring the jumping of electrons with spin-σ between lattice sites is obtained when the motion of electrons with spin σ is considered. The mean field approximation is applied to get the quasi-particle spectrum of the Hamiltonian. The results are compared with those of the zero-temperature Green's methods, and the possibility of insulator-metal transition at finite temperature is investigated.

关 键 词：HUBBARD模型 准粒子 平均场近似 

分 类 号：O482[理学—固体物理]