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 non-equilibrium 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 efficient heat engine. Furthermore, the interplay of Rashba spin-orbit coupling and Zeeman splitting due to an external magnetic field is shown to allow control over such parameters of the heat engine as the power and efficiency.