Zero-field spin splitting in an inverted In0.53Ga0.47As/In0.52Al0.48As heterostructure: Band nonparabolicity influence and the subband dependence

Abstract
A gated inverted In0.52Al0.48As/In0.53Ga0.47As/In0.52Al0.48As quantum well is studied via magnetotransport. By analyzing the gate-voltage-dependent beating pattern observed in the Shubnikov–de Haas oscillation, we determine the gate voltage (or electron concentration) dependence of the spin-orbit coupling parameter α. Our experimental data and its analysis show that the band nonparabolicity effect cannot be neglected. For electron concentrations above 2×1012cm2, it causes a reduction of α up to 25%. We report the α value for the second subband.