Anomalous spin and charge Seebeck effect in a quantum well with spin orbit interaction

摘要

We discuss the possible existence of an anomalously high low-temperature charge and spin thermopower in a two dimensional electron system with Rashba and Dresselhaus spin-orbit coupling in the special case when the two interactions have equal strengths. The fundamental premise of the theory is the establishment of an weak itinerant antiferromagnetic order in the ground state, a spin alignment favored in the minimum-energy many-body state when the Coulomb interaction is considered. The transport in this state is modeled by using the solutions of a Boltzmann equation obtained within the relaxation time approximation. We show that when scattering on magnetic impurities is introduced, the energy dependence of the relaxation time enhances the value of the thermoelectric coefficient for both charge and spin currents. An estimate of the effect is provided for the case of a standard InAs quantum well and its variation with the strength of the magnetic scattering is studied.