【摘要】 本文计算了准周期原胞超晶格中横弹性波的体和面模式的色散关系,导出了用传输矩阵表述的动力学格林函数,并用以计算了热涨落的谱密度。结果表明由于系统对于垂直于超晶格轴的平面不存在反映对称性,当表面截取在原胞内F_m个不同的界面上时(F_m是Fibonacci数)半无限样品的横声子表面谱呈现F_m种截然不同的形式。更多还原

【Abstract】 The dispersion relations of transverse elastic wave in both infinite and semi-infinite quasiperiodic superlattice is discussed by the rational approximation, and the dynamical elastic Gree’s function for a semi-infinite superlattice with quasiperiodic primary cell is obtained and used to calculate the spectral density of thermal fluctuations. The results show that because of the break of reflection symmetry in the plane perpendicular to the axis of the superlattice, when the surface is located at Fm different interfaces of the primary cell (Fm is the Fibonacci number), the dispersion spectra of surface transverse phonon show the existence of Fm patterns for each choice of sets of the parameters.更多还原