Discrete gap breathers in a two-dimensional diatomic face-centered square lattice

作者：Lue Bin Bin; Tian Qiang

来源：Chinese Physics B, 2009, 18(10): 4393-4406.

DOI：10.1088/1674-1056/18/10/049

• discrete gap breathers
• two-dimensional diatomic face-centered square lattice
• linear stability
• coupling parameters

In this paper we study the existence and stability of two-dimensional discrete gap breathers in a two-dimensional diatomic face-centered square lattice consisting of alternating light and heavy atoms, with on-site potential and coupling potential. This study is focused on two-dimensional breathers with their frequency in the gap that separates the acoustic and optical bands of the phonon spectrum. We demonstrate the possibility of the existence of two-dimensional gap breathers by using a numerical method. Six types of two-dimensional gap breathers are obtained, i.e., symmetric, mirror-symmetric and asymmetric, whether the center of the breather is on a light or a heavy atom. The difference between one-dimensional discrete gap breathers and two-dimensional discrete gap breathers is also discussed. We use Aubry's theory to analyze the stability of discrete gap breathers in the two-dimensional diatomic face-centered square lattice.

• 出版日期2009-10
• 单位北京师范大学