Magnetophotocurrent in BiTeI with Rashba spin-split bands

Abstract

Magnetophotocurrent with possible spin polarization is generated at room temperature by breaking the time-reversal symmetry of bulk spin-split bands. The band gap excitation in a layered polar semiconductor BiTeI with a large bulk Rashba spin splitting generates a directional photocurrent flowing along the direction orthogonal to both the in-plane magnetic field and crystal polar axis. The direction of this charge current can be flipped by reversing the magnetic field. The photocurrent is found to be independent of light polarization, and ascribed to the $k$-dependent relaxation of nonequilibrium carriers in the Zeeman-shifted spin-split bands.