Thermal Spin-Transfer Torque in Magnetoelectronic Devices

We predict that the magnetization direction of a ferromagnet can be reversed by the spin-transfer torque accompanying spin-polarized thermoelectric heat currents. We illustrate the concept by applying a finite-element theory of thermoelectric transport in disordered magnetoelectronic circuits and devices to metallic spin valves. When thermalization is not complete, a spin heat accumulation vector is found in the normal-metal spacer, i.e., a directional imbalance in the temperature of majority and minority spins.

Figure 1

Schematic of a noncollinear $F({\mathbf{m}}_1)|N|F({\mathbf{m}}_2)$ spin valve. Spin-dependent resistive elements separate the ferromagnetic reservoirs and the normal-metal node. A temperature bias induces a spin accumulation in the form of heat and angular momentum imbalance, the interplay of which is governed by inelastic scattering.