Effect of Phonon Focusing on the Thermal Conductivity of GaAs/AlGaAs Heterostructures at Low Temperatures

Abstract

The effect of the anisotropy of elastic properties on the thermal conductivity of GaAs/AlGaAs heterostructures at low temperatures is investigated. The effect of phonon focusing on the anisotropy of the thermal conductivity is analyzed. The parameters of the specular reflection of phonons from the boundaries of the heterostructures, which characterize the heat flux in the Knudsen mode of the phonon gas flow, are determined. The angular dependences of the mean free paths of phonons of different polarizations, which determine the thermal conductivity anisotropy of heterostructures with orientations {100} and {110}, are calculated.