Cyclotron resonance of carbon-doped two-dimensional hole systems: From the magnetic quantum limit to low magnetic fields

Abstract

We report on cyclotron resonance (CR) experiments of high-quality C-doped two-dimensional hole systems in GaAs/AlGaAs quantum wells covering the microwave and far-infrared regimes. At high magnetic field B we observe a strong B dependence of the cyclotron mass mc which can be reproduced by calculations based on a 4×4 Luttinger Hamiltonian in the axial approximation. At small B one main and up to three secondary CRs are found, which continuously evolve with smooth magnetic-field dependences. This has not been observed and predicted so far. In the regime of the magnetic quantum limit a further CR is observed, which can be attributed to a transition between Landau levels originating from the two different spin-split heavy- and light-hole subbands.