An investigation of tunable spin–orbit interactions in front-gated In0.75Ga0.25As/In0.75Al0.25As heterojunctions

We investigated zero-field spin-splitting in normal-type In0.75Ga0.25As/In0.75Al0.25As heterostructure by magnetoresistance measurements at View the MathML source. The maximum value of spin–orbit interaction parameter, αzero, obtained here is View the MathML source. We also confirmed a tuning of αzero by applying gate biases. On the other hand, we observed no beat oscillation when the In0.75Ga0.25As well width decreased from 30 to View the MathML source. These results suggested that interface contribution related to the asymmetry of wave function penetration into the barriers could be enhanced in our heterojunction.