title: Importance of charge fluctuations for the topological phase in SmB(6).
abstract: Typical Kondo insulators (KIs) can have a nontrivial Z_{2} topology because the energy gap opens at the Fermi energy (E_{F}) by a hybridization between odd- and even-parity bands. SmB_{6} deviates from such KI behavior, and it has been unclear how the insulating phase occurs. Here, we demonstrate that charge fluctuations are the origin of the topological insulating phase in SmB_{6}. Our angle-resolved photoemission spectroscopy results reveal that with decreasing temperature the bottom of the d-f hybridized band at the X[over ¯] point, which is predicted to have odd parity and is required for a topological phase, gradually shifts from below to above E_{F}. We conclude that SmB_{6} is a charge-fluctuating topological insulator.
authors.affiliation: Universität Würzburg, Experimentelle Physik VII, 97074 Würzburg, Germany and Karlsruhe Institut für Technologie KIT, Gemeinschaftslabor für Nanoanalytik, 76021 Karlsruhe, Germany.
authors.forename: Chul-Hee
authors.initials: CH
authors.lastname: Min
authors.affiliation: Universität Würzburg, Experimentelle Physik VII, 97074 Würzburg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Lutz
authors.affiliation: Universität Würzburg, Experimentelle Physik VII, 97074 Würzburg, Germany and Karlsruhe Institut für Technologie KIT, Gemeinschaftslabor für Nanoanalytik, 76021 Karlsruhe, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Fiedler
authors.affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
authors.forename: B Y
authors.initials: BY
authors.lastname: Kang
authors.affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
authors.forename: B K
authors.initials: BK
authors.lastname: Cho
authors.affiliation: Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Republic of Korea and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea.
authors.forename: H-D
authors.initials: HD
authors.lastname: Kim
authors.affiliation: Universität Würzburg, Experimentelle Physik VII, 97074 Würzburg, Germany and Karlsruhe Institut für Technologie KIT, Gemeinschaftslabor für Nanoanalytik, 76021 Karlsruhe, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Bentmann
authors.affiliation: Universität Würzburg, Experimentelle Physik VII, 97074 Würzburg, Germany and Karlsruhe Institut für Technologie KIT, Gemeinschaftslabor für Nanoanalytik, 76021 Karlsruhe, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Reinert