Nonlinear gap modes in a 1D alternating bond monatomic lattice with anharmonicity

作者：Pan, LX^*; Zhou, GH; Xia, QL; Yan, JR

来源：Communications in Theoretical Physics, 2001, 35(5): 609-614.

• diamond-structure lattice
• nonlinear gap modes
• quasi-continuum approximation

We analytically study the nonlinear localized gap modes in a one-dimensional atomic chain with uniform atomic mass but two periodically alternating force constants between the nearest neighbors by means of a quasi-continuum approximation. This model simulates a row of atoms in the (111) direction of a diamond-structure type of crystals or molecular crystals with alternating double and single bonds. For this lattice system, rye find that the harmonic plus quartic anharmonic terms of inter-site potential produce a new type of nonlinear localized gap modes with a slightly asymmetry distribution of atomic displacements. These localized gap modes are somewhat different from widely studied localized gap modes with a symmetry atomic displacement distribution in diatomic ion lattices.

• 出版日期2001-5-15
• 单位湖南师范大学; 中南大学; 湖南城市学院