Seebeck effect, spin Seebeck effect and spin-electronics

セーベック効果,スピン・セーベック効果,スピン・エレクトロニクス

前川 禎通

Maekawa, Sadamichi

In the Seebeck effect, the electric voltage is generated in a conductor placed in a temperature gradient. The efficiency of the effect is given by the density and the scattering of the conduction electrons in usual metals and semiconductors. Since the Seebeck effect is due to the entropy carried by the electric current, the spin and orbital degrees of freedom of conducting electrons in the oxides may enhance the Seebeck effect. In the presentation, firstly, the enhanced Seebeck effect is discussed in the transition metal oxides. Secondly, the spin-Seebeck effect is proposed, where the spin voltage is generated in a ferromagnetic metal placed in a temperature gradient. Then by utilizing the spin-detection method based on the spin-Hall effect, the spin voltage is converted to the electric voltage. The spin-Seebeck effect is induced by a pure spin current, a flow of electron spin without electric charge current, and provides a variety of spin-electronics applications.