Spin-splitting transport in In 0.75Ga 0.25As/In 0.75Al 0.25As quantum wire field-effect-transistor

Abstract

We have made quantum wire field-effect-transistor (QWR-FET) in normal-type In 0.75Ga 0.25As/In 0.75Al 0.25As modulation-doped heterostructure and investigated spin-splitting properties by low-temperature magnetoresistance (MR) measurements. Maximum value of zero-field spin–orbit coupling constant, α zero, obtained here is 78 (×10 −12 eVm). We also confirmed an in-plane anisotropy of α zero, that is, different α zeros in between 〈 1 ̄ 1 0〉 and 〈1 1 0〉 directed samples and a reduction of α zero by applying negative gate biases. In MR measurements, we also observed conductance fluctuations superimposing on the beat oscillation in the sample with widths less than 2 μm.