BALLISTIC PHONON TRANSPORT THROUGH GAUSSIAN ACOUSTIC NANOCAVITIES

We investigate ballistic phonon transport through Gaussian acoustic nanocavities in a semiconductor nanowire at low temperatures. When the transverse widths of acoustic nanocavities takes a Gaussian function, it is found that wide band gap and resonant peaks appear in transmission spectra. The phonon-cavity confined modes exist as the number of the nanocavities is large. The phonon transmission and thermal conductance strongly depend on the number and length of nanocavities. The results suggest that the Gaussian acoustic nanocavities may be useful for controlling thermal conductance artificially and the design of phonon devices to manipulate ballistic phonons in nanophononics.