Přejít k obsahu

4D texture of circular dichroism in soft-x-ray photoemission from tungsten

FEDCHENKO, O. V., MEDJANIK, K., CHERNOV, S. V., KUTNYAKHOV, D., ELLGUTH, M., OELSNER, A., SCHÖNHENSE, B., PEIXOTO, T. R., LUTZ, P., MIN, C. H., REINERT, F. T., DÄSTER, S., ACREMANN, Y. M., VIEFHAUS, J., WURTH, W., BRAUN, J., MINÁR, J., EBERT, H., ELMERS, H. J., SCHÖNHENSE, G. 4D texture of circular dichroism in soft-x-ray photoemission from tungsten. NEW JOURNAL OF PHYSICS, 2019, roč. 21, č. JAN 18 2019, s. NESTRÁNKOVÁNO. ISSN: 1367-2630
Jazyk publikace: eng
Anglický název: 4D texture of circular dichroism in soft-x-ray photoemission from tungsten
Rok vydání: 2019
Autoři: Olena V. Fedchenko , Katerina Medjanik , Sergey V. Chernov , Dmytro Kutnyakhov , Martin Ellguth , Andreas Oelsner , Benedikt Schönhense , Thiago R.F. Peixoto , Peter Lutz , Chul-hee Min , Friedrich T. Reinert , Simon Däster , Yves M. Acremann , Jens Viefhaus , Wilfried Wurth , Jürgen Braun , doc. Dr. Jan Minár , Hubert Ebert , Hans Joachim Elmers , Gerd Schönhense
Abstrakt CZ: Prezentujeme detailnú 4D analýzu cirkulárneho dichroizmu meraného vo fotoemisii woflramu(110). Fotoemisia bola meraná pre fotónové energie od 300-1300eV. Experimentálne dáta boli porovnané s výpočtami vrámci jednokrokového modelu fotoemisie.
Abstrakt EN: Photoemission-intensity distributions I-RCP/LCP (E-B, k) measured for right- and left-circularly polarized soft x-rays revealed a large circular dichroism in angular distribution (CDAD) in the 4D parameter space (E-B binding energy, k momentum vector). Full-field k-imaging combined with time-of-flight energy recording at a high-brilliance soft x-ray beamline allowed mapping the CDAD in the bulk Brillouin zone of tungsten and the entire d-band complex within a few hours. CDAD-asymmetries are very high (up to 90%), persist throughout the whole photon-energy range (300-1300 eV) and show a pronounced dependence on momentum k and binding energy E-B, visualized as movies or sequences of cuts through the 4D object. One-step photoemission calculations for the same photon energies show fair agreement with the measured results. In addition to the requirement of a 'handed' experimental geometry, known from previous experiments on adsorbates and surface states, we find an anti-symmetric behavior of the CDAD with respect to two bulk mirror planes. A new symmetry condition along the perpendicular momentum k(z) makes CDAD a valuable tool for an unambiguous identification of high-symmetry planes in direct transitions in the periodic zone scheme. Technically, the method provides a circular polarimeter for soft, tender and hard x-rays.
Klíčová slova