Ballistic phonon transport in dielectric membranes

We have calculated the ballistic phononic heat transport in dielectric membranes as a function of radiator temperature and membrane thickness. The phonon modes of such membranes are known as Lamb-modes from elasticity theory. The striking result is that, for a fixed temperature, the radiated power first decreases with decreasing membrane thickness, but then develops a minimum when the transition to two dimensionality is reached. Further decrease of the membrane thickness in the 2D limit leads to increasing radiated power. (c) 2006 Elsevier B.V. All rights reserved.