Proposed manipulation of spin currents in GaAs crystal using the Pockels effect

A spin current could induce linear electro-optical electric susceptibility, thus the incident light could interact with the spin current via Pockels effect. In this letter, we find by appropriately selecting the directions of the applied electric field, the propagation direction of the incident light and its polarization, there will exist spin angular momentum transfer between the incident light and the spin polarized electrons resulting in the change of the spin current. Basing on this, a method for manipulating spin current is put forward. In our method, we could adjust the magnitude of the applied electric field or the intensity of incident light to manipulate the spin currents. The numerical results show that, for the condition of the applied electric field being 1×103 Vm-1 and the intensity of incident light being 1×105 Wm-2, the ratio of the changed pure spin current versus initial pure spin current will drop to 0.1%, and the spin polarization of the generated spin-polarized current will reach to 99.9%.