Effect of the evanescent modes on ballistic thermal transport in quantum structures

Using the scattering matrix method, we investigate the effect of the evanescent modes on ballistic transport probability and thermal conductance in T-shaped and concavity-shaped quantum structures at low temperatures. The results show that the evanescent modes play different roles in the transport possibility and the thermal conductance in both T-shaped and concavity-shaped quantum structures. The evanescent modes can enhance thermal conductance in the concavity-shaped structure and suppress thermal conductance in the T-shaped structure. A brief analysis of these results is given. (C) 2008 American Institute of Physics.