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

Citace:
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
Druh: ČLÁNEK
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.
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