Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, 117576 Singapore, Singapore.
Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
Phys Rev Lett. 2018 Jun 29;120(26):266802. doi: 10.1103/PhysRevLett.120.266802.
We explore the second order bilinear magnetoelectric resistance (BMER) effect in the d-electron-based two-dimensional electron gas (2DEG) at the SrTiO_{3}(111) surface. We find evidence of a spin-split band structure with the archetypal spin-momentum locking of the Rashba effect for the in-plane component. Under an out-of-plane magnetic field, we find a BMER signal that breaks the sixfold symmetry of the electronic dispersion, which is a fingerprint for the presence of a momentum-dependent out-of-plane spin component. Relativistic electronic structure calculations reproduce this spin texture and indicate that the out-of-plane component is a ubiquitous property of oxide 2DEGs arising from strong crystal field effects. We further show that the BMER response of the SrTiO_{3}(111) 2DEG is tunable and unexpectedly large.
我们在 SrTiO_{3}(111) 表面的 d 电子二维电子气 (2DEG) 中探索了二阶双线性磁电电阻 (BMER) 效应。我们发现了具有典型 Rashba 效应的自旋分裂能带结构的证据，对于平面内分量。在面外磁场下，我们发现了打破电子色散六重对称性的 BMER 信号，这是存在依赖于动量的面外自旋分量的特征。相对论电子结构计算再现了这种自旋结构，并表明面外分量是氧化物 2DEG 的普遍特性，这是由于强晶体场效应引起的。我们进一步表明，SrTiO_{3}(111) 2DEG 的 BMER 响应是可调的，而且出乎意料地大。
