Regensburg 2016 – scientific programme
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DS: Fachverband Dünne Schichten
DS 38: Topological Insulators
(Joint session of DS, HL, MA, O and TT, organized by MA)
DS 38.4: Talk
Wednesday, March 9, 2016, 15:45–16:00, H32
Surface preparation and momentum microscopy of the topological Kondo insulator SmB6 — •Christian Tusche1, 2, Martin Ellguth1, Fumitoshi Iga3, and Shigemasa Suga2, 4 — 1Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany — 2Peter Grünberg Institut PGI-6, Forschungszentrum Jülich, 52425 Jülich, Germany — 3College of Science, Ibaraki University, Japan — 4Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
The strongly correlated rare-earth compound SmB6 is believed to be a topological Kondo insulator, where a topologically non-trivial surface state lives in the hybridization gap at low temperatures. While most experimental studies rely on cleaved surfaces, high resolution- and spin resolved photoemission experiments [1] usually suffer from the short live time of the reactive surface at low temperatures.
Here we present the reproducible surface preparation of large high quality SmB6 single crystals by in-situ Ar-ion sputtering and controlled annealing. In particular, Sm-rich or B-rich surface terminations are obtained by low (≈1080∘C) or high (>1200∘C) temperature annealing. Using a momentum microscope [2], wide wave vector regions are studied by photoemission with He-I (hν=21.2 eV) and laser (hν=6.0 eV) excitations, on the Sm-terminated surface. The results reveal localized f-electron resonances at EF and strong hybridization, paving the way to measure detailed Fermi surface and valence band spin textures.
[1] Suga et al., J., Phys. Soc. Japan 83, 014705 (2014)
[2] C. Tusche, A. Krasyuk, J. Kirschner, Ultramicroscopy (2015)