摘要
用 Mean-field hopping 的近似方法研究了同格点电子相关对 Anderson无序系统的影响。在半满带下得到了金属-绝缘转变相图。结果表明,同格点的吸引作用(U<0)有利于 Anderson 局域态的形成;排斥的相互作用(U>0)在低温下破坏Anderson 局域态的形成。还发现,很小的无序就需要较大的相关能来实现 Hubbard绝缘相。
The effect of on-site electron correlation on Anderson's disorder system was studied by use of an approximate solution so-called Mean-field hopping. Phase diagrams of metal-insulator transition are obtained subject to a half-filled band. The results show that for the formation of Anderson's localized state, the on-site attractive interaction (U<0) will favour it but the repulsive interaction (U> will destroy it at a low temperature. Also, great correlation energy is required for the weak disorder to attain to Hubbard insulating phase.
关键词
Anderson无序
H-绝缘相
局域态
Anderson disorder, localized states,Hubbard insulating phase, 'quenched-type'average.
