Discrete breathers in a model with Morse potentials  

作　　者：吕彬彬 邓艳平 田强 

机构地区：[1]Department of Physics,Beijing Normal University

出　　处：《Chinese Physics B》2010年第2期381-387,共7页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 1057411);the Foundation for Researching Group by Beijing Normal University

摘　　要：Under harmonic approximation, this paper discusses the linear dispersion relation of the one-dimensional chain. The existence and evolution of discrete breathers in a general one-dimensional chain are analysed for two particular examples of soft （Morse） and hard （quartic） on-site potentials. The existence of discrete breathers in one-dimensional and two-dimensional Morse lattices is proved by using rotating wave approximation, local anharmonic approximation and a numerical method. The localization and amplitude of discrete breathers in the two-dimensional Morse lattice with on-site harmonic potentials correlate closely to the Morse parameter a and the on-site parameter к.Under harmonic approximation, this paper discusses the linear dispersion relation of the one-dimensional chain. The existence and evolution of discrete breathers in a general one-dimensional chain are analysed for two particular examples of soft （Morse） and hard （quartic） on-site potentials. The existence of discrete breathers in one-dimensional and two-dimensional Morse lattices is proved by using rotating wave approximation, local anharmonic approximation and a numerical method. The localization and amplitude of discrete breathers in the two-dimensional Morse lattice with on-site harmonic potentials correlate closely to the Morse parameter a and the on-site parameter к.

关 键 词：discrete breathers Morse lattice square lattice on-site potential 

分 类 号：O469[理学—凝聚态物理]