Thermoelectric response of spin polarization in Rashba spintronic systems

Abstract

Motivated by the recent discovery of a strongly spin–orbit-coupled two-dimensional (2D) electron gas near the surface of Rashba semiconductors BiTeX (X= Cl, Br, I), we calculate the thermoelectric responses of spin polarization in a 2D Rashba model. By self-consistently determining the energyand band-dependent transport time, we present an exact solution of the linearized Boltzmann equation for elastic scattering. Using this solution, we find a non-Edelstein electric-field-induced spin polarization that is linear in the Fermi energy E_F when E_F lies below the band crossing point. The spin polarization efficiency, which is the electric-field-induced spin polarization divided by the driven electric current, increases for smaller E_F .We show that, as a function of E_F, the temperaturegradient-induced spin polarization increases continuously to a saturation value when EF decreases below the band crossing point. As the temperature tends to zero, the temperature-gradient-induced spin polarization vanishes.

Keywords

thermoelectric response / spin polarization / Rashba spin–orbit coupling / Boltzmann equation / analytical solution

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