Discrete breathers in a two-dimensional Morse lattice with an on-site harmonic potential

Abstract

Two-dimensional discrete breathers in a two-dimensional Morse lattice with on-site harmonic potentials are investigated. Under the harmonic approximation, the linear dispersion relations for the triangular and the square lattices are discussed. The existence of discrete breathers in a two-dimensional Morse lattice with on-site harmonic potentials is proved by using local inharmonic approximation and the numerical method. The localization and amplitude of two-dimensional discrete breathers correlate closely to the Morse parameter a and the on-site parameter κ.

Keywords

two-dimensional discrete breathers / triangular lattice / square lattice / Morse lattice / on-site harmonic potential