Thermoelectric properties of a quantum dot coupled to magnetic leads by Rashba spin-orbit interaction

Abstract

We consider a single-level quantum dot coupled to two leads which are ferromagnetic in general. Apart from tunneling processes conserving electron spin, we also include processes associated with spin flip of tunneling electrons, which appear due to Rashba spin-orbit coupling. Charge and heat currents are calculated within the nonequilibrium Green's function technique. When the electrodes are half metallic (fully spin polarized), the Rashba spin-orbit coupling leads to Fano-like interference effects, which result in an enhanced thermoelectric response. It is also shown that such a system can operate as a heat engine with a remarkable efficiency. Furthermore, the interplay of Rashba spin-orbit coupling and Zeeman splitting due to an external magnetic field is shown to allow controlling of such parameters of the heat engine as the power and efficiency.