边界条件对介电量子波导中声子输运性质的影响

Effect of boundary conditions on phonon transmission in a dielectric quantum waveguide

运用散射矩阵方法,研究了Neumann边界条件和Dirichlet边界条件在低温下对结构不连续的纳米结构中的声学声子输运系数的影响.数值结果表明,当边界条件不同时,声学声子输运系数会有极大的不同;在一定的结构条件下,由于声子模与模的耦合作用,出现了共振透射和禁止频带.

We investigate the effect of boundary conditions on the low temperature phonon transport in a quantum waveguide with structural defects by using the scattering-matrix method. A comparison between transmission coefficients is made when Neumann and Dirichlet boundary conditions are applied for acoustic modes, respectively. The result indicates that the behavior of the transmission coefficient versus reduced phonon frequency is qualitatively different for different boundary conditions. The stop- frequency gap and the transmission resonance are observed for certain structural parameters due to mode-mode coupling.