Modeling of Polarization-Specific Phonon Transmission Through Interfaces

In this work, the atomistic Green's function method is extended to compute transmission functions for each phonon polarization. The eigenvectors and eigenvalues of the overall density of states matrices are manipulated to yield a density of states matrix for each polarization. A decomposed self-energy is calculated from the density of states matrix for each polarization and used to calculate the transmission function for a particular phonon branch. In a pure bulk material such as silicon, each transmission function exhibits a frequency-independent value of unity. In heterogeneous bulk materials, the transmission function is reduced significantly due to the junction of dissimilar materials. [DOI: 10.1115/1.4004400]