Ballistic thermal transport in asymmetric Y-branch three terminal junction

The thermal transport properties of Y-branch three terminal junction are studied by using the scattering-matrix method for in-plane waves. The mode conversion has been considered for two transmitted components (P wave and SV wave). The results show that the phonon mode separation behavior exists not only at low incident frequencies but also at high incident frequencies. The non-integer quantization thermal conductance has been found. Furthermore, the transmission coefficients of acoustic phonon in both branches can be modulated by the phonon nanocavity length L. The work suggests that such Y-branch structure can be act as a thermal shunt.