Surface acoustic waves in metals

Abstract

The authors present propagation experiments for surface acoustic waves (SAW) in pure single crystals of aluminium and gallium. Geometric resonances and de Haas-van Alphen oscillations are observed as sound velocity changes. In addition, a typical surface effect, a nonreciprocal effect of the SAW velocity with respect to applied field and propagation direction reversal, is observed. A theory is given which explains this effect quantitatively.