Thermal transport across metal-insulator interface via electron-phonon interaction

The thermal transport across a metal-insulator interface can be characterized by electron-phonon interaction through which an electron lead is coupled to a phonon lead if phonon-phonon coupling at the interface is very weak. We investigate the thermal conductance and rectification between the electron part and the phonon part using the nonequilibrium Green's function method. It is found that the thermal conductance has a nonmonotonic behavior as a function of average temperature or the coupling strength between the phonon leads in the metal part and the insulator part. The metal-insulator interface shows a clear thermal rectification effect, which can be reversed by a change in average temperature or the electron-phonon coupling.