电子-晶格耦合非线性项对极化子性质的影响  

Effects of nonlinear electron-lattice interaction on polarons

作　　者：宋瑞[1,2] 刘晓静[1,2] 王亚东[1,2] 邸冰[1,2] 安忠[1,2] 

机构地区：[1]河北师范大学物理科学与信息工程学院,石家庄050016 [2]河北新型薄膜材料实验室,石家庄050016

出　　处：《物理学报》2010年第5期3461-3465,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10574037;10747125);新世纪优秀人才支持计划;河北省杰出青年基金(批准号:A2009001512)资助的课题~~

摘　　要：基于一维紧束缚SSH模型,讨论了电子晶格耦合二阶项对极化子静态和动力学性质的影响:随着二阶项系数β的增加,二聚化常数越来越大,能隙越来越宽,极化子的局域性不断增强,但带宽几乎没有变化.动力学方面由于二阶项的引入增强了电声相互作用,随着β值的增大,极化子的运动速度减小,并且极化子的解离电场不断增大.Based on the Su-Schrieffer-Heeger （ SSH ） model extended to include the square term of the electron-lattice interaction,the dynamic characteristics of polarons are investigated. With increasing of the coefficient of the square term （β）,the energy gap between the valance band and the conduction band increases. but the total width of the energy band does not change. At the same time,it is found that the dimerization amplitude and the localization of polarons are strengthened by the nonlinear electron-lattice interaction. Furthermore,the results show that the polaron velocity is suppressed by the nonlinear electron-lattice interaction,and the critical electric field strength to dissociate the polaron increases with β increasing.

关 键 词：SSH模型 电-声耦合二阶项 极化子 

分 类 号：TN383.1[电子电信—物理电子学]