Finger-gate manipulated quantum transport in a semiconductor narrow constriction with spin-orbit interactions and Zeeman effect

The authors investigate quantum transport in a narrow constriction fabricated by narrow-band-gap semiconductor materials with spin-orbit couplings. We consider the Rashba-Dresselhaus (RD) spin-orbit interactions (SOIs) and the Zeeman effect induced by an in-plane magnetic field along the transport direction. The interplay of the RD SOI and the Zeeman effect may induce a SOI-Zeeman gap and influence the transport properties. We demonstrate that an attractive scattering potential may induce an electronlike quasi-bound-state feature and manifest the RD-SOI-Zeeman induced Fano line shape in conductance. Furthermore, a repulsive scattering potential may induce a holelike quasi-bound-state feature on the subband top of the lower spin branch.