New types of surface acoustoelectric waves and acoustic charge transport in GaAs crystals

It is shown for the first time that longitudinal and transverse surface acoustoelectric waves can propagate in the basal plane of GaAs crystals. In contrast to well-known Gulyaev-Bleustein transverse waves, these waves are localized in a surface layer with a thickness on the order of the wavelength. The field of mechanical displacements and the electric-potential field of the wave are shifted in phase by π/2. The electric-field vector is circularly polarized in the sagittal plane. The effect of acoustoelectric charge transport by wave packets of new-type acoustoelectric waves is considered.