Spin analogs of thermo-magnetoelectric phenomena for heat switches

Abstract

The study of novel thermal effects associated with spin current is fundamental to understanding the relationship between magnetoelectric and thermal phenomena. The central focus of attention of our research is on the spin analog of the Thomson effect as the most promising in terms of its use in heat switches of solid-state coolers. In order to model heat flows, the heat conduction equation is derived in the presence of magnetic and electric fields. Applying the developed theoretical framework, the spin Thomson coefficient is calculated for a yttrium-iron garnet plate. It is demonstrated that this coefficient strongly depends on the thickness of the plate. The corresponding estimates of the heat flux carried by the spins are also obtained. For a 200 nm plate, it is 6.81 W/cm2, which is comparable to the heat fluxes in the best thermal switches. Moreover, the results of the paper indicate at the possibility of further increase in the flux by an optimal choice of plate thickness and magnitude of magnetic field.