Experimental and theoretical approach to spin splitting in modulation-doped ${\mathrm{In}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As/InP quantum wells for B→0

Spin splitting of conduction-band energy levels in a modulation-doped InP/${\mathrm{In}}_{0.77}$${\mathrm{Ga}}_{0.23}$As/InP quantum well has been studied by Shubnikov–de Haas oscillations. By analyzing the characteristic beating pattern of the oscillations the coupling constant α for spin-orbit interaction was determined. Biasing a gate on top of a Hall bar was used to modify the strength of the spin-orbit coupling. The measured spin-orbit coupling parameter α is quantitatively explained by utilizing a refined envelope-function-approximation theory for heterostructures.