Polarization Dependence of Shear-Wave Attenuation by Open-Orbit Electrons in Cu

Abstract

The strength of measured resonant-attenuation peaks for ultrasonic shear waves caused by open-orbit electrons in Cu is shown to be related to the component of electron motion in the direction of sound polarization. The direction of the applied magnetic field is irrelevant except in determining the orbit geometry. The open orbit in Cu for $\stackrel{\ensuremath{\rightarrow}}{\mathrm{B}}\ensuremath{\parallel}[101]$ has a much larger component of motion along $\stackrel{\ensuremath{\rightarrow}}{\mathrm{B}}$ than perpendicular to it, so that interpretations of data based on motion in the plane perpendicular to $\stackrel{\ensuremath{\rightarrow}}{\mathrm{B}}$ fail.