Tusche Christian, Krasyuk Alexander, Kirschner Jürgen
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany; Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, 06099 Halle, Germany.
Ultramicroscopy. 2015 Dec;159 Pt 3:520-9. doi: 10.1016/j.ultramic.2015.03.020. Epub 2015 Mar 24.
We present a spin resolving "momentum microscope" for the high resolution imaging of the momentum distribution of photoelectrons. Measurements of the band structure of a Au(111) single crystal surface demonstrate an energy resolution of ΔE=12 meV and a momentum resolution of Δk∥=0.0049 Å(-1), measured at the line-width of the spin-orbit split Shockley surface state. The relative accuracy of the k∥ measurement in the order of 10(-4) Å(-1) reveals a deviation from the ideal two-dimensional free electron gas model of the Shockley surface state, manifested in a threefold radial symmetry. Spin resolution in the full momentum image is obtained by an imaging spin-filter based on low-energy electron diffraction at a Au passivated Ir(100) single crystal. Using working points at 10.5 eV and 11.5 eV scattering energy with a completely reversed asymmetry of ±60% we demonstrate the efficient mapping of the spin texture of the Au(111) surface state.
我们展示了一种用于光电子动量分布高分辨率成像的自旋分辨“动量显微镜”。对Au(111)单晶表面能带结构的测量表明，在自旋轨道分裂的肖克利表面态的线宽处测得的能量分辨率为ΔE = 12 meV，动量分辨率为Δk∥ = 0.0049 Å⁻¹。k∥测量的相对精度约为10⁻⁴ Å⁻¹，揭示了与肖克利表面态的理想二维自由电子气模型的偏差，表现为三重径向对称性。通过基于Au钝化的Ir(100)单晶上低能电子衍射的成像自旋滤波器，在全动量图像中获得了自旋分辨率。利用10.5 eV和11.5 eV散射能量下具有±60%完全相反不对称性的工作点，我们展示了Au(111)表面态自旋纹理的有效映射。
