Quantum oscillations in magnetoacoustic attenuation of degenerate piezoelectric semiconductors

Abstract

Effects of parabolic and nonparabolic band structures on ultrasonic waves propagating at an angle θ relative to the direction of a dc magnetic fieldB in a degenerate semiconductor such as n-type InSb are investigated by using a quantum treatment which is valid at high frequencies and in strong magnetic fields. The interaction of conduction electrons with ultrasonic waves is via deformation-potential and piezoelectric couplings. It is found that the absorption coefficient and change in sound velocity oscillate with the dc magnetic field when ultrasonic waves propagate along the dc magnetic field for both parabolic and nonparabolic band structures. However, when the angle θ is different from zero, the absorption coefficient and change in sound velocity for the parabolic band structure do not oscillate with the magnetic field, due to the reduction of the component of the sound wave vector along the magnetic field, and those for the nonparabolic band structure will still oscillate with the magnetic field, due to the nonlinear effect of the energy eigenvalue equation.