Giant oscillations of the rate of sound attenuation in layered conductors placed in a magnetic field

The propagation of sound waves in layered conductors with quasi-two-dimensi onal electron energy spect a is studied theoretically. It is shown that in a magnetic held H the rate of sound attenuation G oscillates with a great a mplitude as a function of 1/H and of the angle between H and the sound wave vector k, if the charge carriers are capable of drifting along k, and the r adius of curvature of their trajectories r is much less than the electron m ean free path l but significantly exceeds the wavelength of sound 1/k. The diameter of the Fermi surface in the direction orthogonal to the vectors k and H can be determined to a high degree of accuracy from the measured peri od of the oscillations.