1. A consistent view of the samarium hexaboride terminations to resolve the nature of its surface states
- Author
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Herrmann, H., Hlawenka, P., Siemensmeyer, K., Weschke, E., Sánchez-Barriga, J., Varykhalov, A., Shitsevalova, N. Y., Dukhnenko, A. V., Filipov, V. B., Gabáni, S., Flachbart, K., Rader, O., Sterrer, M., and Rienks, E. D. L.
- Subjects
Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,FOS: Physical sciences - Abstract
The research effort prompted by the prediction that SmB$_6$ could be the first topological Kondo insulator has produced a wealth of new results, though not all of these seem compatible. A major discrepancy exists between scanning tunneling microscopy / spectroscopy (STM/S) and angle-resolved photoemission spectroscopy (ARPES), because the two experimental methods suggest a very different number of terminations of the (100) surface with different properties. Here we tackle this issue in a combined STM/S and ARPES study. We find that two of the well-ordered topographies reported in earlier STM studies can be associated with the crystal terminations identified using photoemission. We further observe a reversal of the STM contrast with bias voltage for one of the topographies. We ascribe this result to a different energy dependence of Sm and B-derived states, and show that it can be used to obtain element specific images of SmB$_6$ and identify which topography belongs to which termination. We finally find STS results to support a modification of the low-energy electronic structure at the surface that has been proposed as the trivial origin of surface metallicity in this material., Comment: 7 pages, 5 figures
- Published
- 2018
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