Acoustic phonon transport and thermal conductance in one-dimensional quantum waveguide modulated with quantum dots

Abstract

By using scattering matrix method, we compare the propertics of acoustic phonon transport and thermal conductance in one-dimensional quantum waveguide modulated with both convex-shape and concave-shape quantum structures. The results show that the transmission spectra and thermal conductances are sensitive to the geometric structures of quantum dots, and the transmission rate and thermal conductance KCV in the convex-shape quantum structure are bigger than the transmission rate and thermal conductance KCC in the concave-shape quantum structure. The thermal conductance ratio KCV/KCC is dependent on the geometric detail of quantum dot, and the ratio increases with the increase of difference in side-length of the cross section between the quantum dot and the main quantum waveguide. The difference in thermal transport between the convex-shape and the concave-shape quantum structures originates from more excited dilatational acoustic modes in the convex-shape quantum structure than in the concave-shape quantum structure.