RESONANT TRANSMISSION OF ACOUSTIC PHONONS IN MULTISUPERLATTICE STRUCTURES

We study theoretically the resonant transmission of acoustic phonons in multisuperlattice (SL) systems. As a typical structure, the stack ABA of the periodic SL's A and B is considered. A periodic SL is known to exhibit a strong filtering action on the phonons in the stop bands. Hence, in this multi-SL system, A SL's act as barriers for phonons in their stop bands (A stop bands). However, we show that those phonons in A stop bands are transmitted very efficiently through this system when they satisfy the resonance condition determined by the structure of the sandwiched B SL. This is analogous to the resonant tunneling of electrons in multiple-quantum-well structures. We demonstrate these results by calculating both the frequency and angular dependences of phonon transmission.