Nonlinear Zeeman Splitting of Holes in Doped GaAs Heterostructures

Polarization-resolved photoluminescence from two-dimensional GaAs/GaAlAs heterostructures doped with acceptors was studied in high magnetic fields. Measurements were carried out in low temperatures up to 2 K and magnetic field up to 21 T. Experiments performed in the Faraday configuration enabled to resolve hole states with different spin orientation. We observed a nonlinear behavior of valence-band g factor in strong magnetic fields. To explain obtained results, a detailed theoretical calculation was carried out based on the Luttinger model for valence-band states. We examined the spin splitting of hole levels under the influence of both external magnetic field and built-in electric field existing in doped heterostructures. Changes of hole g factor with the width of the structure and the density of two-dimensional carriers are discussed