A Brillouin study of the angular dispersion of generalized surface and pseudosurface acoustic waves on the (001) surface of InSb

The velocity angular dispersion of the generalized surface (GSW) and pseudo surface (PSW) acoustic waves on the (001) plane of InSb has been measured b y Brillouin scattering. The complete range of angular dispersion of these w aves on the (001) plane of an anisotropic cubic crystal has been experiment ally determined. The p-p and p-s polarization results accord well with theo ry. In particular, the measured angular dispersion of these surface modes t races out two separate and distinct branches, in contrast to one single cur ve arising from the branching from GSW to PSW, normally observed for anisot ropic cubic crystals. (C) 2000 American Institute of Physics. [S0003-6951(0 0)04535-6].