An investigation of the anisotropy of the valence band of GaAs by cyclotron resonance

Cyclotron resonance of the holes in p-GaAs is reported at wavelengths of 2.2 mm and 337 mu m and at liquid nitrogen temperatures. The conditions under which hole cyclotron-resonance measurements can be interpreted as being dominated by classical light and heavy holes are investigated by means of complimentary cyclotron-resonance studies in p-Ge at 337 mu m wavelengths over the temperature range 70-200K. When the ratio of photon energy to thermal energy (h(cross) omega /kT) is about 0.6, weak quantum structure can be observed and the heavy-hole lines observed in certain directions can be shifted from the classical k=0 values by as much as 10%. The bare masses for the light and heavy holes in GaAs, after nonparabolicity and polaron corrections have been carried out, are found.