TY - JOUR
T1 - Surface Kondo effect and non-trivial metallic state of the Kondo insulator YbB12
AU - Hagiwara, Kenta
AU - Ohtsubo, Yoshiyuki
AU - Matsunami, Masaharu
AU - Ideta, Shin Ichiro
AU - Tanaka, Kiyohisa
AU - Miyazaki, Hidetoshi
AU - Rault, Julien E.
AU - Le Fèvre, Patrick
AU - Bertran, François
AU - Taleb-Ibrahimi, Amina
AU - Yukawa, Ryu
AU - Kobayashi, Masaki
AU - Horiba, Koji
AU - Kumigashira, Hiroshi
AU - Sumida, Kazuki
AU - Okuda, Taichi
AU - Iga, Fumitoshi
AU - Kimura, Shin Ichi
N1 - Funding Information:
We thank J. Kishi, Y. Takeno and Y. Negoro for their support during general experiments. For preliminary experiments to obtain a clean sample surface, we thank K. Imura, T. Hajiri and T. Ito for their support. We acknowledge D. Ragonnet and F. Deschamps for their support during the experiments on the CASSIOPÉE beamline at the SOLEIL synchrotron. We also thank S. Wu and T. Yoshikawa for their support for the spin-resolved ARPES measurements at HiSOR. Part of the ARPES experiments were performed under UVSOR Proposal Nos. 26-540 and 27-542 and Photon Factory Proposal No. 2015G540. This work was also supported by the JSPS Grant-in-Aid for Scientific Research Activity Start-up (Grant No. JP26887024), (B) (Grant No. JP15H03676) and the Murata Science Foundation.
Publisher Copyright:
© 2016 The Author(s).
PY - 2016/8/31
Y1 - 2016/8/31
N2 - A synergistic effect between strong electron correlation and spin-orbit interaction has been theoretically predicted to realize new topological states of quantum matter on Kondo insulators (KIs), so-called topological Kondo insulators (TKIs). One TKI candidate has been experimentally observed on the KI SmB6 (001), and the origin of the surface states (SS) and the topological order of SmB6 has been actively discussed. Here, we show a metallic SS on the clean surface of another TKI candidate YbB12 (001) using angle-resolved photoelectron spectroscopy. The SS shows temperature-dependent reconstruction corresponding to the Kondo effect observed for bulk states. Despite the low-temperature insulating bulk, the reconstructed SS with c-f hybridization is metallic, forming a closed Fermi contour surrounding Γ on the surface Brillouin zone and agreeing with the theoretically expected behaviour for SS on TKIs. These results demonstrate the temperature-dependent holistic reconstruction of two-dimensional states localized on KIs surface driven by the Kondo effect.
AB - A synergistic effect between strong electron correlation and spin-orbit interaction has been theoretically predicted to realize new topological states of quantum matter on Kondo insulators (KIs), so-called topological Kondo insulators (TKIs). One TKI candidate has been experimentally observed on the KI SmB6 (001), and the origin of the surface states (SS) and the topological order of SmB6 has been actively discussed. Here, we show a metallic SS on the clean surface of another TKI candidate YbB12 (001) using angle-resolved photoelectron spectroscopy. The SS shows temperature-dependent reconstruction corresponding to the Kondo effect observed for bulk states. Despite the low-temperature insulating bulk, the reconstructed SS with c-f hybridization is metallic, forming a closed Fermi contour surrounding Γ on the surface Brillouin zone and agreeing with the theoretically expected behaviour for SS on TKIs. These results demonstrate the temperature-dependent holistic reconstruction of two-dimensional states localized on KIs surface driven by the Kondo effect.
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U2 - 10.1038/ncomms12690
DO - 10.1038/ncomms12690
M3 - Article
AN - SCOPUS:84985027785
SN - 2041-1723
VL - 7
JO - Nature Communications
JF - Nature Communications
M1 - 12690
ER -