A consistent view of the samarium hexaboride terminations to resolve the nature of its surface states
| Autor: | 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., Rienks, E. D. L. |
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| Rok vydání: | 2018 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | 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 |
| Databáze: | arXiv |
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