Effect of defects on the thermal conductivity in a nanowire

We investigate the effect of defects on the low temperature thermal conductance in nanowire structure by using the scattering-matrix method. It is found the behavior of the thermal conductance versus temperature is qualitatively different for different types of defects. When the defect is void, the universal quantum thermal conductance and the decrease of the thermal conductance at low temperature can be clearly observed. However, when the structural defect consists of clamped material, the quantized thermal conductance cannot be observed, and the thermal conductance increases monotonically with increasing temperature.