Dependence of electron effective mass on the subband occupation in In0.53Ga0.47As/InP quantum wells

We investigated the in-plane electron effective mass m∗ of InGaAs/InP multi-quantum wells in dependence on the subband occupation, varied by n-doping. We expect an influence of the InGaAs conduction-band nonparabolicity, as well as of the subband splitting. m∗ has been evaluated and analysed by highly resolved Shubnikov–de Haas (SdH) oscillations in magnetic fields up to View the MathML source. We use a correction for the observed dependence m∗(B) and determine m∗ at B=0. The carrier concentratin n of our samples, as measured by Hall effect (H) and compared to SdH results, extends from nH=4.3×1011 to View the MathML source. We observed two subbands, as clearly confirmed by two different SdH periods at View the MathML source. For the lower subband, m∗ increases markedly from 0.047me to 0.060me. However, for the bottom of the second subband, observed at View the MathML source is reduced to 0.047me. It increases again to 0.073me at View the MathML source.