Effect of laser annealing on specular and diffuse scattering of 285 GHz phonons at polished silicon surfaces

Abstract

We have investigated the time resolved backscattering of high frequency phonons (greater-or-equal, slanted 285 GHz) at laser annealed silicon surfaces at low temperatures. It is found that the scattering off the free surface becomes predominantly specular up to frequencies well above 285 GHz and that the anomalous transmission into liquid helium (Kapitza effect) is strongly reduced.