title: Non-Kondo-like electronic structure in the correlated rare-earth hexaboride YbB(6).
abstract: We present angle-resolved photoemission studies on the rare-earth-hexaboride YbB(6), which has recently been predicted to be a topological Kondo insulator. Our data do not agree with the prediction and instead show that YbB(6) exhibits a novel topological insulator state in the absence of a Kondo mechanism. We find that the Fermi level electronic structure of YbB(6) has three 2D Dirac cone like surface states enclosing the Kramers's points, while the f orbital that would be relevant for the Kondo mechanism is ∼1  eV below the Fermi level. Our first-principles calculation shows that the topological state that we observe in YbB(6) is due to an inversion between Yb d and B p bands. These experimental and theoretical results provide a new approach for realizing novel correlated topological insulator states in rare-earth materials.
authors.affiliation: Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Madhab
authors.initials: M
authors.lastname: Neupane
authors.affiliation: Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Su-Yang
authors.initials: SY
authors.lastname: Xu
authors.affiliation: Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Nasser
authors.initials: N
authors.lastname: Alidoust
authors.affiliation: Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Guang
authors.initials: G
authors.lastname: Bian
authors.affiliation: Department of Physics and Astronomy, University of California at Irvine, Irvine, California 92697, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: I
authors.initials: I
authors.lastname: Belopolski
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: T-R
authors.initials: TR
authors.lastname: Chang
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan and Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: H-T
authors.initials: HT
authors.lastname: Jeng
authors.affiliation: Condensed Matter and Magnet Science Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: T
authors.initials: T
authors.lastname: Durakiewicz
authors.affiliation: Graphene Research Centre, Department of Physics, National University of Singapore, Singapore 117542, Singapore.
authors.forename: H
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bansil
authors.affiliation: Department of Physics and Astronomy, University of California at Irvine, Irvine, California 92697, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Fisk
authors.affiliation: Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA and Princeton Center for Complex Materials, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: M Z
authors.initials: MZ
authors.lastname: Hasan