Magnetic-circular-dichroism study of heavy- and light-hole g factorsinInxGa1

Intersubband transitions in ${\mathrm{In}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As/InP quantum wells have been studied by magnetic circular dichroism (MCD) of the absorption. The g values of the heavy and light holes in the different subbands are deduced from the intensity dependence of the MCD signals on the applied magnetic field: ${\mathrm{g}}_{\mathrm{hh}1}^{\mathrm{*}}$=-0.68\ifmmode\pm\else\textpm\fi{}0.1, ${\mathrm{g}}_{\mathrm{hh}2}^{\mathrm{*}}$=-1.81\ifmmode\pm\else\textpm\fi{}0.4, and ${\mathrm{g}}_{\mathrm{lh}1}^{\mathrm{*}}$=8.87\ifmmode\pm\else\textpm\fi{}1.2. These results are in good agreement with effective-mass-theory calculations and allow one to estimate the in-plane effective masses of the second heavy-hole (${\mathrm{m}}_{\mathrm{hh}2}^{\mathrm{*}}$=0.${85\mathrm{m}}_{0}$) and the first light-hole (${\mathrm{m}}_{\mathrm{lh}1}^{\mathrm{*}}$=0.${17\mathrm{m}}_{0}$) subbands. An observed increase of the half-width of the subband transitions with increasing transition energy and increasing magnetic field is qualitatively explained by statistical fluctuations of the quantum-well width.