Electrical manipulation of spin polarization and generation of giant spin current using multi terminal spin injectors

Two advantages of the lateral spin valve using multi-terminal spin injections have been demonstrated. First, the effective spin polarization for the pure spin current can be controlled by the two anti-parallely aligned spin injectors. We show that the magnitude and the sign of the spin polarization are electrically manipulated by adjusting the current ratio between two injectors. Secondly, we show that the giant pure spin current can be generated by the nonlolcal spin injections from the quadruple spin injectors.