Beatings of Shubnikov-de Haas oscillations in a two-dimensional hole system in an InGaAs quantum well

The magnetoresistance of an InGaAs/GaAs heterostructure with a two-dimensional hole channel has been measured in quantizing magnetic fields. Beatings of Shubnikov-de Haas oscillations have been observed, which indicate that the spin degeneracy of the system is lifted owing to the spin-orbit interaction. The oscillation pattern is independent of the magnetic field component parallel to the two-dimensional system; this independence is characteristic of size-quantization heavy-hole subbands.