Subharmonic phonon transmission and Kapitza conductance between crystals with very different vibrational spectra

The low frequency resonant intrinsic vibrational modes are predicted to exist at the interface between two crystals with strongly different elastic properties. The interface resonant mode can stimulate the subharmonic nonlinear transmission of acoustic phonons and generation of the phonons with frequencies multiple to the resonant frequency. These inelastic processes can substantially contribute to the Kapitza thermal boundary conductance between solids with very different vibrational spectra (such as diamond and soft crystal) and to the thermal conductance across a helium-solid interface also. (author). 25 refs