Effect of energy-band structures on the propagation of ultrasound in degenerate semiconductors

The effect of parabolic and nonparabolic band structures on the propagation of ultrasound at an angle theta relative to the direction of a dc magnetic field B in a degenerate semiconductor such as n-type InSb is investigated by using a quantum treatment which is valid at high frequencies and in strong magnetic fields. Numerical results show that the absorption coefficient and change in sound velocity depend strongly on the direction of the propagation of ultrasound relative to the magnetic field for both parabolic and nonparabolic band structures. However, the absorption coefficient and change in sound velocity for the nonparabolic band structure will diminish and become small in the intermediate-magnetic-field region when the angle theta is larger than 300