Spin galvanic effect at the conducting SrTiO3 surfaces

TL;DR

This paper demonstrates significant spin-charge conversion at the conducting SrTiO3 surface induced by Ar+ irradiation, highlighting its potential for oxide spintronics due to Rashba spin-orbit coupling effects.

Contribution

It provides experimental evidence of large spin-charge conversion efficiency at SrTiO3 surfaces, emphasizing the role of Rashba effect and surface properties in oxide spintronics.

Findings

Large spin-charge conversion observed at SrTiO3 surface

Rashba effect enables efficient charge-spin conversion

Surface properties enhance spintronic potential

Abstract

The (001) surface of SrTiO3 were transformed from insulating to conducting after Ar+ irradiation, producing a quasi two-dimensional electron gas (2DEG). This conducting surface layer can introduce Rashba spin orbital coupling due to the broken inversion symmetry normal to the plane. The spin splitting of such a surface has recently been demonstrated by magneto-resistance and angular resolved photoemission spectra measurements. Here we present experiments evidencing a large spin-charge conversion at the surface. We use spin pumping to inject a spin current from NiFe film into the surface, and measure the resulting charge current. The results indicate that the Rashba effect at the surface can be used for efficient charge-spin conversion, and the large efficiency is due to the multi-d-orbitals and surface corrugation. It holds great promise in oxide spintronics.