A microscopic formulation of the phonon transmission at the nanoscale

We present a microscopic approach for estimating the frequency vs. wave-vector dependent phonon transmission across a solid-solid interface. We show that the spectral properties of the heat flux can be generally deduced from the equilibrium displacements fluctuations of the contact atoms. We have applied and demonstrated our formalism with molecular dynamics simulations to predict the angular and mode dependent phonon transport in silicon and germanium thin films. This notably unveils the existence of confined interface mode at the thermal contacts. (C) 2013 AIP Publishing LLC.