Gaussian superlattice for phonons

A recently developed long-wavelength continuum phenomenological model is employed to study the phonon tunneling through semiconductor heterostructures where the barrier parameters are varied gradually according to a Gaussian function. The optical modes of a Si/SixGe1Kx Gaussian superlattice are considered. Such structures allow the incident phonons to be nearly totally transmitted when the incident phonon frequency is in the passband. Analog Gaussian superlattices for electrons have motivated recent interesting studies. By adjusting the parameters of the superlatice, the desire passband and stopband can be obtained. Thus, our study could be useful for the design of phonon optics devices. q 2005 Published by Elsevier Ltd. PACS: 63.20.Dj; 63.22.Cm; 68.65.Cg