Giant forward-scattering asymmetry and anomalous tunnel Hall effect at spin-orbit-split and exchange-split interfaces

Abstract

We report on theoretical investigations of scattering asymmetry vs incidence of carriers through exchange barriers and magnetic tunnel junctions made of semiconductors involving spin-orbit interaction. By an analytical $2\ifmmode\times\else\texttimes\fi{}2$ spin model, we show that when Dresselhaus interaction is included in the conduction band of antiparallel magnetized electrodes, the electrons can undergo a large difference of transmission depending on the sign of their incident in-plane wave vector. In particular, the transmission is fully quenched at some points of the Brillouin zone for specific in-plane wave vectors and not for the opposite. Moreover, the asymmetry is universally scaled by a unique function independent of the spin-orbit strength. This particular feature is reproduced by a $14\ifmmode\times\else\texttimes\fi{}14$ band $\mathbf{k}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbf{p}$ model showing, in addition, corresponding effects in the valence band and highlighting the robustness of the phenomenon, which even persists for a single magnetic electrode. Upon tunneling, electrons undergo an asymmetrical deflection which results in the occurrence of a transverse current, giving rise to a so-called tunnel Hall effect.