Giant spin-orbit torque and spin current generation in carriers at oxide interfaces

Abstract

Interfacing polar insulating oxides may result in the formation of interface-confined, high density carriers with a number of emergent properties. A local coupling of carriers to a helimagnetic oxide layer is shown to lead to an effective spin-orbit interaction with a band splitting determined by the local s-d exchange interaction. As a result a bias-induced, non-equilibrium long-lived spin density normal to the spiral plane is predicted. We find that the spin accumulation is strongly enhanced when only one of the two bands is at the Fermi level and the chemical potential is close to the band edge. As a consequence we predict a large spin-transfer torque and spin current emission that can be utilized for oxide-based spintronic applications.