Spin polarization induced by in-plane electric and magnetic fields in two-dimensionalheavy-hole systems

Abstract

Using a nonequilibrium Green function approach, we systematically investigate the currentinduced spin polarization (CISP) in a two-dimensional heavy-hole system with cubicRashba spin–orbit coupling, driven by in-plane electric and magnetic fields. We find thatwhen a magnetic field is applied along the direction of electric field, the longitudinalconductivity drops monotonously with an increase of magnetic-field strength or of holedensity. The spin polarization along the electric-field direction is just the Pauliparamagnetism and it quadratically increases with an increase of hole density. Thenonvanishing out-of-plane component of spin polarization emerges for both short-range andlong-range disorders, and it changes sign with the variation of magnetic field, especially forlong-range hole-impurity scattering. In the magnetic-field dependences of this out-of-planeCISP and of the in-plane CISP perpendicular to the electric field, there are singularmagnetic fields, below or above which the effects of magnetic field are completelydifferent.