Spin Current and Spin Hall Effect in Metallic Nano-Structures

Laterally configured ferromagnetic/nonmagnetic multiterminal structures have great potential for developing future spintronic devices. We demonstrate two kinds of novel spintronic devices. One is a lateral spin valve with noncollinear dual spin injectors by which the direction of the spin accumulation in a nonmagnetic metal can be changed by varying the currents injected by two spin injectors. The other is a transformer between spin and charge currents using the spin Hall effect. A large spin Hall conductivity of 260 S/cm at room temperature, which is 10⁴ times larger than that in semiconductor systems, is found in the Pt wire. We also demonstrate the reciprocal relation between the spin and charge currents. Temperature dependence of the spin Hall conductivity is also discussed.