绝热极限下HMMC链中的量子晶格涨落效应  

EFFECT OF QUANTUM LATTICE FLUCTUATIONS ON HMMC CHAIN IN ADIABATIC LIMIT CASE

作　　者：王沁[1] 刘吉超[1] 

机构地区：[1]新疆师范大学物理系,乌鲁木齐830054

出　　处：《新疆师范大学学报（自然科学版）》1998年第4期15-21,41,共8页Journal of Xinjiang Normal University(Natural Sciences Edition)

摘　　要：准一维HMMC链的物理结构和相互作用特点决定着系统各种对称破缺基态存在的可能性。为分析电声子相互作用和二聚化位移,从Hamiltonian模型出发,采用正则变换和位移变换,引进电子一声子散射函数,对绝热极限条件下HMMC链系统进行了研究。讨论了系统的二聚化相变、能隙、准粒子激发能谱等,并根据基态能量应满足的变分极值条件,得到确定格点位移二聚化序参量的自洽方程。结果表明,在绝热极限情况下,当电声子耦合强度很小时,系统的二聚化非常弱。随着电声子耦合强度的不断增强,系统的二聚化程度不断增大。The phsical properties,structure characteristics and interactions of quasi-one-dimensional HMMC chains determine the existence possibilities of various symmetry -broken ground states of HMMC chain system Based on the tight-binding Hamitonian model,the adiabatic limit of HMMC chain has been studied by introducing unitary and displacement transformation methods and the dimerization transition,energy gap,excitation spectrum of fermions and selfconsistent equation are attained. The result shows that ,in the case of adiabatic limnit, dimerization extent of the system increases when electron-phonon coupling constant increases gradually.

关 键 词：量子晶格涨落 绝热极限 序参量 电声子耦合 

分 类 号：O481[理学—固体物理]