Insights from angle-resolved photoemission spectroscopy on the metallic states of YbB6(001): E(k) dispersion, temporal changes, and spatial variation Frantzeskakis, E.; de Jong, N.; Zhang, J.X.; Zhang, X.; Li, Z.; Liang, C.L.; Wang, Y.; Varykhalov, A.; Huang, Y.; Golden, M.S.
Published in:Physical Review B
DOI:10.1103/PhysRevB.90.235116
Link to publicationCitation for published version (APA): Frantzeskakis, E., de Jong, N., Zhang, J. X., Zhang, X., Li, Z., Liang, C. L., ... Golden, M. S. (2014). Insights from angle-resolved photoemission spectroscopy on the metallic states of YbB6(001): E(k) dispersion, temporal changes, and spatial variation. Physical Review B, 90(23), 235116. https://doi.org/10.1103/PhysRevB.90.235116
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Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. We report high-resolution angle-resolved photoelectron spectroscopy (ARPES) results on the (001) cleavage surface of YbB 6 , a rare-earth compound that has been recently predicted to host surface electronic states with topological character. We observe two types of well-resolved metallic states, whose Fermi contours encircle the time-reversal invariant momenta of the YbB 6 (001) surface Brillouin zone, and whose full E(k) dispersion relation can be measured wholly unmasked by states from the rest of the electronic structure. Although the two-dimensional character of these metallic states is confirmed by their lack of out-of-plane dispersion, our work reveals two aspects which were not observed in previous experiments. First, these states do not resemble two branches of opposite, linear velocity that cross at a Dirac point, but rather straightforward parabolas that terminate to high binding energy with a clear band bottom. Secondly, these states are sensitive to time-dependent changes of the YbB 6 surface under ultrahigh-vacuum conditions. Adding the fact that these data from cleaved YbB 6 surfaces also display spatial variations in the electronic structure, it appears there is little in common between the theoretical expectations for an idealized YbB 6 (001) crystal truncation on the one hand, and these ARPES data from real cleavage surfaces on the other.
