二维声学极化子自陷判据的重新构建  

Re-established Criteria of Self-trapping Transition of Acoustic Polaron in Two Dimensional System

作　　者：段晓峰[1] 侯俊华[1] DUAN Xiaofeng;HOU Junhua(College of Physics and Information Engineering,Shanxi Normal University,Linfen 041004,Shanxi China)

机构地区：[1]山西师范大学物理与信息工程学院,山西临汾041004

出　　处：《河南科学》2018年第3期311-315,共5页Henan Science

基　　金：国家自然科学基金(11147159);山西省高等学校科技创新项目(20161104)

摘　　要：从二维晶格振动的"简谐近似"的描述出发,考虑电子-声学声子的库伦型相互作用,从源头推导得到了新的描述二维电子-声学声子耦合的哈密顿量.采用类Huybrechts变分法讨论了二维声学极化子自陷的可能性.结果表明:二维声学极化子由自由态向自陷态转变对应的临界电子-声子耦合常数随声子截止波矢的增大而减小;二维声学极化子自陷比三维情况要容易.The Hamiltonian of electron-acoustic phonon interaction in two dimensional system is reconfirmed.The possibility of the self-trapping transition on the acoustic polaron in two dimensional system is investigated by the Huybrechts-like variational approach.It is indicated that the position of the critical point is sensitive to the cut-off wave vector and moves towards the direction of smaller electron phonon coupling with the increasing cut-off wave vector.The self-trapping transition of the acoustic polaron in two dimensional system is easier than that in three dimensional system.

关 键 词：二维声学极化子 电子-声学声子耦合 自陷转变 

分 类 号：O471.3[理学—半导体物理]