中国物理B ›› 2010, Vol. 19 ›› Issue (2): 26302-026302.doi: 10.1088/1674-1056/19/2/026302

• • 上一篇    下一篇

Discrete breathers in a model with Morse potentials

吕彬彬, 邓艳平, 田强   

  1. Department of Physics, Beijing Normal University, Beijing 100875, China
  • 收稿日期:2009-04-09 修回日期:2009-06-02 出版日期:2010-02-15 发布日期:2010-02-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 1057411), and the Foundation for Researching Group by Beijing Normal University.

Discrete breathers in a model with Morse potentials

Lü Bin-Bin(吕彬彬), Deng Yan-Ping(邓艳平), and Tian Qiang(田强)   

  1. Department of Physics, Beijing Normal University, Beijing 100875, China
  • Received:2009-04-09 Revised:2009-06-02 Online:2010-02-15 Published:2010-02-15
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 1057411), and 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.

Abstract: 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 $\kappa$.

Key words: discrete breathers, Morse lattice, square lattice, on-site potential

中图分类号:  (Localized modes)

  • 63.20.Pw
63.20.D- (Phonon states and bands, normal modes, and phonon dispersion) 63.20.Ry (Anharmonic lattice modes)