准周期对spin-Peierls模型中晶格畸变和能隙的影响

The effect of quasiperiodicity on lattice distortion and energy gap in spin-Peierls model

采用严格对角化方法和自洽方法,研究准周期相互作用对spin-Peierls模型中晶格畸变和能隙的影响.研究表明,引入准周期作用后,spin-Peierls模型中晶格畸变和能谱表现出准周期结构的自相似特性.另外,在弹性系数K取不同值时,随着准周期作用强度的增强,晶格畸变的平均值可能会增大、减小或先增大后减小,其对应的能隙也有相似的行为.

The effect of quasiperiodic interaction on lattice distortion and energy gap in spin-Peierls model is studied by exact diagonalization and self-consistent methods. It is shown that quasiperiodic interaction can result in self-similar characteristics for lattice distortion and energy spectra of spin-Peierls model. Moreover, we find that the average value of lattice distortion will be increased, decreased or increased firstly then decreased as quasiperiodic interaction strength is enhanced. Such kind of behavior strongly depends on the lattice spring constant K. The energy gap also displays similar behavior.