Phonon transport properties of a mass–spring simple cubic nanocrystal within the harmonic approximation

We present a theoretical description of phonon transport for a mass–spring simple cubic nanocrystal which is embedded between two semi-infinite similar leads within the harmonic approximation. It is supposed that the structure is constructed from mass–spring layers which are connected to each other by identical springs. By using the free boundary conditions for the masses on the surface, we obtain the phonon density of states/modes and transmission coefficient of ideal quasi-1D and 2D systems. Then, we investigate the influence of some parameters of the system like masses and spring constants in the layers on the phonon transport properties. The results reveal that, in contrast with increasing of the allowed phonon band frequency, increasing the spring constants in the layers decreases the phonon transmission coefficient.