Probing and tuning inelastic phonon conductance across finite-thickness interface

Abstract

Phonon transmission across an interface between dissimilar crystalline solids\nis calculated using molecular dynamics simulations with interatomic force\nconstants obtained from first principles. The results reveal that although\ninelastic phonon-transmission right at the geometrical interface can become far\ngreater than the elastic one, its contribution to thermal boundary conductance\n(TBC) is severely limited by the transition regions, where local phonon states\nat the interface recover the bulk state over a finite thickness. This suggests\nTBC can be increased by enhancing phonon equilibration in the transition region\nfor instance by phonon scattering, which is demonstrated by increasing the\nlattice anharmonicity.\n