Intraband and interband magneto-optics of p-type ${\mathrm{In}}_{0.18}$${\mathrm{Ga}}_{0.82}$As/GaAs quantum wells

p-type 90-Å ${\mathrm{In}}_{0.18}$${\mathrm{Ga}}_{0.82}$As/GaAs quantum wells with carrier concentrations in the range ${\mathit{p}}_{\mathit{s}}$=(1.5–4.3)×${10}^{11}$ ${\mathrm{cm}}^{\mathrm{-}2}$ have been studied by magneto-optics. Cyclotron resonance measures the effective mass of the ‖${\mathit{M}}_{\mathit{J}}$‖=3/2 holes as ≃0.16 for in-plane motion. The mass is light because of the strain decoupling of the ‘‘heavy-hole’’ ‖${\mathit{M}}_{\mathit{J}}$‖=3/2 and ‘‘light-hole’’ ‖${\mathit{M}}_{\mathit{J}}$‖=1/2 states. The effective mass has been measured as a function of carrier concentration and field. The totally decoupled limit is not achieved and the residual coupling between the ‖${\mathit{M}}_{\mathit{J}}$‖=3/2 and 1/2 states is well described by a calculation of the Landau levels using an eight-band k⋅p model. Filling-factor-related anomalies in the cyclotron resonance are observed and interpreted in terms of hole-hole interactions combined with the presence of localizing potentials. Interband photoconductivity measurements determine the conduction-band structure and good agreement with the calculations is achieved. The magnetoexciton binding energy and band filling are considered in the analysis of the interband data.