Orientation effect in ultrasonic attenuation by degenerated conductors

The resonant absorption of the sound wave energy is investigated in metals with open Fermi surface and low-dimensional conductors placed in a magnetic field, when the radius of an electron orbit is much less than the mean fre e path of charge carriers but exceeds significantly the sound wavelength. W hen the sound wave vector is not orthogonal to the magnetic field the displ acement of the resonance peaks occurs, their magnitude being dependent not only on the charge carriers energy spectrum but on the sound wave frequency . Investigations of the zero-line of absorption in the range of the frequen cies, which are comparable with the frequency of collisions of conducting e lectrons, enable the detailed information on the charge carriers energy spe ctrum to be obtained. (C) 2000 Published by Elsevier Science B.V. All right s reserved.