Resonant Landau–Zener transitions in a helical magnetic field

Spin-dependent electron transport has been studied in magnetic semiconductor waveguides (nanowires) in the helical magnetic field. We have shown that—apart from the well-known conductance dip located at the magnetic field equal to the helical-field amplitude B_h—the additional conductance dips (with zero conductance) appear at a magnetic field different from B_h. This effect occurring in the non-adiabatic regime is explained as resulting from the resonant Landau–Zener transitions between the spin-split subbands. (paper)