Spin current and spin Seebeck effect

Maekawa, Sadamichi

When metals and semiconductors are placed in a temperature gradient, the electric voltage is generated. This mechanism to convert heat into electricity, the so-called Seebeck effect, has attracted much attention as the mechanism for utilizing wasted heat energy. Ferromagnetic insulators are good conductors of spin current, i.e., the flow of electron spins. When they are placed in a temperature gradient, generated are spin current and the spin voltage, i.e., spin accumulation. Once the spin voltage is converted into the electric voltage by the inverse spin Hall effect in attached metal films, the electric voltage is obtained from heat energy. This is called the spin Seebeck effect (SSE). We present the basic concept of SSE and discuss about SSE in a variety of magnetic systems.