Investigation of size and electronic effects on Kapitza conductance with non-equilibrium molecular dynamics

Abstract

In nanosystems, the thermal resistance between materials typically dominates the overall resistance. While size effects on thermal conductivity are well documented, size effects on thermal boundary conductance have only been speculated. In response, we characterize the relationship between interfacial resistance and material dimension using molecular dynamics. We find that the interfacial resistance increases linearly with inverse system length but is insensitive to cross-sectional area. Also, from the temperature-dependence of interfacial resistance, we conclude that contributions of short-wavelength phonons dominate. Lastly, by coupling the molecular dynamics to a two-temperature model, we show that electron-mediated transport has little effect on thermal resistance.