Heat conduction and phonon localization in disordered harmonic crystal
Abstract:
We investigate the system size dependence of the heat current in two and three dimensional disordered harmonic crystals. Both nonequilibrium simulations as well as direct numerical evaluation of phonon transmission coefficients are performed. In the presence of a pinning potential we find that Fourier's law is valid in three dimensions while in two dimensions we obtain a heat insulator. In the absence of pinning the heat conductivity is found to have a power-law divergence with system size and our study suggests the presence of super-diffusive phonon states. Some results on heat conduction in anharmonic crystals will be briefly discussed.