Open AccessSolving dispersion relations of one-dimensional diatomic chain with on-site potential by invariant eigen-operator method
Author(s) -
Yanjie Ren,
Hong-Yi Fan
Publication year - 2013
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.62.156301
Subject(s) - diatomic molecule , invariant (physics) , operator (biology) , physics , dispersion relation , boundary value problem , lattice (music) , quantum mechanics , mathematical analysis , mathematics , chemistry , biochemistry , repressor , molecule , transcription factor , acoustics , gene
The dispersion law of a one-dimensional diatomic lattice with on-site potential cross on its dispersion relation is solved under the harmonic approximation with quantized invariant eigen-operator method (IEO) and the influences of on-site potential and force constant are discussed. It is shown that due to the existence of on-site potential the lattice vibration spectra induced are shifted. Under certain conditions, the point of intersection exist between optical branch and acoustic branch in the boundary of Brillioun zone, which means the frequency gap between optical branch and acoustic branch is zero.