Effects of localization and mesoscopic phenomena on ultrasonic attenuation in a disordered piezoelectric metal

We propose the use of surface-acoustic-wave attenuation at subkelvin temperatures for the study of localization and mesoscopic phenomena in GaAs/${\mathrm{Al}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As heterojunctions. Based on the piezoelectric properties of GaAs, we present a diagrammatic interpretation of electronic absorption in terms of coupling of the lattice strain to the electric current.