A New Formalism for Calculating Modal Contributions to Thermal Interface Conductance from Molecular Dynamics Simulations

A new formalism for extracting the modal contributions to thermal interface conductance with full inclusion of anharmonicity is presented. The results indicate that when two materials are joined a new set of vibrational modes are required to correctly describe the transport across the interface. Among these new modes, certain classifications emerge, as most modes extend at least partially into the other material. Localized interfacial modes are also present and exhibit the highest conductance contributions on a per mode basis. The results also show that anharmonicity enables inelastic scattering at temperatures as low as 10K and inelastic processes contribute 20% of the conductance for the system studied.