Two-Dimensional Discrete Gap Breathers in a Two-Dimensional Diatomic β  

作　　者：徐权 田强 

机构地区：[1]Department of Physics, Daqing Normal University, Daqing 163712 [2]Department of Physics, Beijing Normal University, Beijing 100875

出　　处：《Chinese Physics Letters》2008年第10期3586-3589,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 1057400 and the Natural Science Foundation of Heilongjiang Province under Grant No A200506.

摘　　要：We study the existence of two-dimensional discrete breathers in a two-dimensional face-centred square lattice consisting of alternating light and heavy atoms, with nearest-neighbour coupling containing quartic soft or hard nonlinearity. This study is focused on two-dimensionai breathers with frequency in the gap that separates the acoustic and optical bands of the phonon spectrum. We demonstrate the possibility of existence of two- dimensional gap breathers by using the numerical method, the local anharmonicity approximation and the rotating wave approximation. We obtain six types of two-dimensional gap breathers, i.e., symmetric, mirror-symmetric and asymmetric, no matter whether the centre of the breather is on a light or a heavy atom.We study the existence of two-dimensional discrete breathers in a two-dimensional face-centred square lattice consisting of alternating light and heavy atoms, with nearest-neighbour coupling containing quartic soft or hard nonlinearity. This study is focused on two-dimensionai breathers with frequency in the gap that separates the acoustic and optical bands of the phonon spectrum. We demonstrate the possibility of existence of two- dimensional gap breathers by using the numerical method, the local anharmonicity approximation and the rotating wave approximation. We obtain six types of two-dimensional gap breathers, i.e., symmetric, mirror-symmetric and asymmetric, no matter whether the centre of the breather is on a light or a heavy atom.

分 类 号：O562[理学—原子与分子物理]