电子关联作用对Jahn-Teller效应引起的结构相变的影响  

INFLUENCE OF ELECTRON-ELECTRON CORRELATION ON THE JAHN-TELLER-TYPE STRUCTURAL PHASE TRANSITIONS

作　　者：吴建斌[1] 

机构地区：[1]浙江大学物理系,杭州310027

出　　处：《物理学报》1991年第9期1474-1484,共11页Acta Physica Sinica

摘　　要：本文从考虑集体Jahn-Teller效应和电子关联作用的哈密顿量出发,研究Jahn-Teller效应所致的结构相变行为随作用量中各参量的变化情况。根据这些参量的不同选择,得到三种结果:(1)体系仅存在对称破缺的一个相变点;(2)体系在高温时存在对称破缺的相变,在低温时对称性又回复;(3)不存在结构相变。Starting from the Hamiltonian of Jahn-Teller effects and electron-electron correlation, we have studied the influence of electron correlation on the structural phase transitions due to the Jahn-Teller effects. By choosing different values of the parameters in the Hamiltonian, we concluded that there exist three possibilities as follows: (1) The system posesses only one structural phase transition, which corresponds to the symmetry breaking. (2) The system has a symmetry-breaking phase transition at high temperature, while the broken symmetry will be revived by decreasing the temperature. (3) The system has no phase transition throughout the whole temperature range.

关 键 词：电子关联 J-T效应 结构相变 

分 类 号：O48[理学—固体物理]