论文标题
Rashba-Split频段的直接可视化和旋转/轨道 - 充电互连在KTAO $ _3 $接口
Direct visualization of Rashba-split bands and spin/orbital-charge interconversion at KTaO$_3$ interfaces
论文作者
论文摘要
Rashba界面已成为通过直接和逆Edelstein效应的旋转电荷互连的有前途的平台。值得注意的是，由运输测量确定，基于氧化物的二维电子气体（2维二元）显示出较大且可调的转换效率。然而，缺乏对氧化物2degs中Rashba分裂带的直接可视化，这阻碍了对它们丰富的自旋轨道物理学的深入了解。在这里，我们研究了KTAO $ _3 $ -2DEGS，并使用角度分辨光发射光谱法证明了他们的Rashba-Split频段。我们将带有紧密结合的哈密顿量安装，我们提取有效的RASHBA系数，并将洞察力带入频带结构的复杂多纤维性质。我们的计算显示非常规的自旋和轨道纹理，显示出很大程度上依赖于平面各向异性的准脱位带对的补偿效应。我们计算带循环的自旋和轨道Edelstein效应，并预测超过其他氧化物2维数的相互转换效率。最后，我们建议Rashba系统的设计规则，以优化旋转电荷互连性能。
Rashba interfaces have emerged as promising platforms for spin-charge interconversion through the direct and inverse Edelstein effects. Notably, oxide-based two-dimensional electron gases (2DEGs) display a large and gate-tunable conversion efficiency, as determined by transport measurements. However, a direct visualization of the Rashba-split bands in oxide 2DEGs is lacking, which hampers an advanced understanding of their rich spin-orbit physics. Here, we investigate KTaO$_3$-2DEGs and evidence their Rashba-split bands using angle resolved photoemission spectroscopy. Fitting the bands with a tight-binding Hamiltonian, we extract the effective Rashba coefficient and bring insight into the complex multiorbital nature of the band structure. Our calculations reveal unconventional spin and orbital textures, showing compensation effects from quasi-degenerate band pairs which strongly depend on in-plane anisotropy. We compute the band-resolved spin and orbital Edelstein effects, and predict interconversion efficiencies exceeding those of other oxide 2DEGs. Finally, we suggest design rules for Rashba systems to optimize spin-charge interconversion performance.
