Nanoscale Heat Conduction Across Metal-Dielectric Interfaces

We report a theoretical study of heat conduction across metal-dielectric interfaces in devices and structures of practical interest. At cryogenic temperatures, the thermal interface resistance between electrodes and a substrate is responsible for substantial reduction in the maximum permissible peak power in Josephson junctions. The thermal interface resistance is much smaller at elevated temperatures but it still plays a critical role in nanoscale devices and structures, especially nanolaminates that consist of alternating metal and dielectric layers. A theoretical model is developed to elucidate the impact of spatial nonequilibrium between electrons and phonons on heat conduction across nanolaminates. The diffuse mismatch model is found to provide reasonable estimates of the intrinsic thermal interface resistance near room temperature as well as at cryogenic temperatures.