Coupling effect on phonon thermal transport in a double-stub quantum wire

By using the scattering matrix method, we investigate the thermal conductance in a double-stub quantum wire at low temperatures. The coupling effects between two stubs are analyzed in detail. It is found that the quantum structures exhibit oscillatory decaying thermal conductance with the width between two stubs at low temperature. A comparison between thermal conductances is made when stress-free and hard-wall boundary conditions are applied for acoustic modes, respectively. The result indicates that the behavior of the thermal conductance versus temperature is qualitatively different for the different types of boundary conditions. (c) 2006 American Institute of Physics.