Effects of Localized Phonons on Interfacial Thermal Conductance

Interfacial thermal conduction is traditionally described by the transmission of traveling phonons in their bulk counterparts. However, recent experiments suggest that localized phonons at an interface may exert a substantial influence on interfacial thermal conductance. By considering quantum phonon scattering processes at a weakly interacting interface, we analyze the role of localized phonons at the interface involved in the interfacial thermal conduction and discover that there is a coupling between traveling phonons and the even orders of the localized phonons at the interface. Using fourth-order localized phonons as an example, we show that the traveling phonons can collide with the localized phonons at the interface. Such collisions can significantly change the transmission probability of the traveling phonons and thus affect the interfacial thermal conductance, and importantly, such effects become increasingly significant with increasing temperature.