Ünzelmann Maximilian, Bentmann Hendrik, Eck Philipp, Kißlinger Tilman, Geldiyev Begmuhammet, Rieger Janek, Moser Simon, Vidal Raphael C, Kißner Katharina, Hammer Lutz, Schneider M Alexander, Fauster Thomas, Sangiovanni Giorgio, Di Sante Domenico, Reinert Friedrich
Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
Institut für Theoretische Physik und Astrophysik and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, 97074 Würzburg, Germany.
Phys Rev Lett. 2020 May 1;124(17):176401. doi: 10.1103/PhysRevLett.124.176401.
The Rashba effect is fundamental to the physics of two-dimensional electron systems and underlies a variety of spintronic phenomena. It has been proposed that the formation of Rashba-type spin splittings originates microscopically from the existence of orbital angular momentum (OAM) in the Bloch wave functions. Here, we present detailed experimental evidence for this OAM-based origin of the Rashba effect by angle-resolved photoemission (ARPES) and two-photon photoemission experiments for a monolayer AgTe on Ag(111). Using quantitative low-energy electron diffraction analysis, we determine the structural parameters and the stacking of the honeycomb overlayer with picometer precision. Based on an orbital-symmetry analysis in ARPES and supported by first-principles calculations, we unequivocally relate the presence and absence of Rashba-type spin splittings in different bands of AgTe to the existence of OAM.
Rashba效应是二维电子系统物理学的基础，也是各种自旋电子学现象的基础。有人提出，Rashba型自旋分裂的形成在微观上源于布洛赫波函数中轨道角动量（OAM）的存在。在这里，我们通过对Ag(111)上单层AgTe进行角分辨光电子能谱（ARPES）和双光子光电子能谱实验，给出了这种基于OAM的Rashba效应起源的详细实验证据。通过定量低能电子衍射分析，我们以皮米精度确定了蜂窝状覆盖层的结构参数和堆积情况。基于ARPES中的轨道对称性分析并得到第一性原理计算的支持，我们明确地将AgTe不同能带中Rashba型自旋分裂的有无与OAM的存在联系起来。
