Intraband and interband magneto-optics of p-type In0.18Ga0.82As/GaAs quantum wells.

Abstract

p-type 90-\AA{} ${\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)\ifmmode\times\else\texttimes\fi{}${10}^{11}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$ have been studied by magneto-optics. Cyclotron resonance measures the effective mass of the \ensuremath{\Vert}${\mathit{M}}_{\mathit{J}}$\ensuremath{\Vert}=3/2 holes as \ensuremath{\simeq}0.16 for in-plane motion. The mass is light because of the strain decoupling of the ``heavy-hole'' \ensuremath{\Vert}${\mathit{M}}_{\mathit{J}}$\ensuremath{\Vert}=3/2 and ``light-hole'' \ensuremath{\Vert}${\mathit{M}}_{\mathit{J}}$\ensuremath{\Vert}=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 \ensuremath{\Vert}${\mathit{M}}_{\mathit{J}}$\ensuremath{\Vert}=3/2 and 1/2 states is well described by a calculation of the Landau levels using an eight-band k\ensuremath{\cdot}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.