Phonon-phonon interaction and thermal conductivity in strongly anisotropic quasi-two-dimensional systems

Abstract

The phonon-phonon interaction and phonon thermal conductivity in strongly anisotropic quasi-two-dimensional systems are considered. Much attention is being given to the low-frequency bending (out-of-plane) phonons which can give rise to a low-temperature local maximum in the $T$ dependence of the in-plane thermal conductivity \ensuremath{\lambda}. The effect of the system anisotropy on \ensuremath{\lambda} is consistently studied. The results lead to an interesting interpretation of the anomalous behavior of the in-plane thermal conductivity in strongly anisotropic systems.