Koitzsch C, Battaglia C, Clerc F, Despont L, Garnier M G, Aebi P
Institut de Physique, Université de Neuchâtel, Rue A.-L. Breguet 1, CH-2000 Neuchâtel, Switzerland.
Phys Rev Lett. 2005 Sep 16;95(12):126401. doi: 10.1103/PhysRevLett.95.126401. Epub 2005 Sep 12.
Quantum well states are a consequence of confinement in a quantum cavity. In this study we investigate with photoemission the influence of the interface electronic structure on the quantum well state energy dispersion in ultrathin Mg(0001) films on W(110). Coupling between the sp-derived quantum well states and the substrate across the interface becomes manifest in a deviation from free electronlike dispersion behavior. Most importantly, we observe a marked level splitting, which is interpreted as due to the Rashba effect at the interface. Such an interfacial electron beam splitting on materials with strong spin-orbit coupling is an essential ingredient for novel spintronic devices. The combination of a quantum cavity with a heavy, electron reflecting substrate reveals spin-splitting effects in ultrathin films without conventional magnetism being involved.
量子阱态是量子腔内受限的结果。在本研究中，我们利用光电子能谱研究了界面电子结构对W(110)上超薄Mg(0001)薄膜中量子阱态能量色散的影响。通过界面的sp衍生量子阱态与衬底之间的耦合在偏离自由电子样色散行为中表现出来。最重要的是，我们观察到明显的能级分裂，这被解释为界面处的Rashba效应所致。这种在具有强自旋轨道耦合的材料上的界面电子束分裂是新型自旋电子器件的一个基本要素。量子腔与重电子反射衬底的结合揭示了超薄薄膜中的自旋分裂效应，而无需涉及传统磁性。
