Anisotropic valence bands in quantum wells: Quantitative comparison of theory and experiment

The valence subband dispersion of GaAs/AlGaAs quantum wells is measured with meV accuracy using the recombination of hot electrons at neutral acceptors. This precision, in combination with polarization-dependent matrix elements, allows direct observation and measurement of the warping. The measurements, for in-plane wave vectors which extend over a substantial fraction of the Brillouin zone, are shown to be in very good agreement with k⋅p calculations.