Magnetically controlled impurities in quantum wires with strong Rashba coupling

We investigate the effect of strong spin-orbit interaction on the electronic transport through nonmagnetic impurities in one-dimensional systems. When a perpendicular magnetic field is applied, the electron spin polarization becomes momentum-dependent and spin-flip scattering appears, to first order in the applied field, in addition to the usual potential scattering. We analyze a situation in which, by tuning the Fermi level and the Rashba coupling, the magnetic field can suppress the potential scattering. This mechanism should give rise to a significant magnetoresistance in the limit of large barriers.

Figure 1

Electron dispersion in the presence of spin-orbit interaction, for $B=0$ (dashed line) and $B\ne 0$ (solid line). If $\alpha k_F⪢g{\mu }_{B}B$, the electron states at the Fermi surface have spins approximately parallel to $+x(\to )$ or $-x(\leftarrow )$.

Figure 2

Resistance of the quantum wire with Rashba coupling constant $\alpha =\hslash v_F$, for a fixed temperature and as a function of the magnetic field $B$.