Spin resolved bandstructure imaging with a high resolution momentum microscope

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 Delta E = 12 meV and a momentum resolution of Delta k(parallel to) = 0.0049 angstrom(-1), measured at the line-width of the spin-orbit split Shockley surface state. The relative accuracy of the k(parallel to) measurement in the order of 10(-4) angstrom(-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. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (hap://creativecommons.org/licenses/by-nc-nd/4.0/).