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.
@article{arxiv.1610.00249,
title = {Spin galvanic effect at the conducting SrTiO3 surfaces},
author = {Wenxu Zhang and Qiuru Wang and Bin Peng and Huizhong Zeng and Wee Tee Soh and Chong Kim Ong and Wanli Zhang},
journal= {arXiv preprint arXiv:1610.00249},
year = {2017}
}