Electrical manipulation of spins in nonmagnetic semiconductors

Electrical manipulation of conduction band electron spins in nonmagnetic semiconductors is achieved by exploiting various manifestations of the spin-orbit interaction. The g-factor engineering combined with bandgap engineering leads to electrical tuning of the g-factor by changing the position of the electron wave function within parabolic quantum wells. Anisotropy of the g-tensor in these structures enables g-tensor modulation resonance through electrical control of the g-tensor. In a complementary approach, the momentum-dependent spin splitting in the conduction band manipulates spins. The strain-induced spin splitting is used to demonstrate coherent rotation of spins, even at zero magnetic field. The effective internal magnetic fields can also be used to drive spin resonance and to electrically polarize electron spins. Also originating from the spin-orbit interaction, the spin Hall effect generates a pure spin current transverse to an applied electric field even in the absence of applied magnetic fields.