Compensation and increase of sound absorption in magnetoacoustic resonance and Doppler-shifted acoustic cyclotron resonance

The Doppler-shifted acoustic cyclotron resonance and magnetoacoustic resonance in metals with a nonconvex Fermi surface are investigated theoretically for an arbitrary form of the deformation potential. The compensation of deformation and electromagnetic resonance contributions to the absorption and dispersion of the velocity of sound is revealed. It is shown that, in addition to the compensation effect in a magnetoacoustic resonance, a considerable increase in the sound absorption may occur due to the vortex fields.