title: Interaction driven subgap spin exciton in the Kondo insulator SmB6.
abstract: Using inelastic neutron scattering, we map a 14 meV coherent resonant mode in the topological Kondo insulator SmB6 and describe its relation to the low energy insulating band structure. The resonant intensity is confined to the X and R high symmetry points, repeating outside the first Brillouin zone and dispersing less than 2 meV, with a 5d-like magnetic form factor. We present a slave-boson treatment of the Anderson Hamiltonian with a third neighbor dominated hybridized band structure. This approach produces a spin exciton below the charge gap with features that are consistent with the observed neutron scattering. We find that maxima in the wave vector dependence of the inelastic neutron scattering indicate band inversion.
authors: Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors: W T
authors: WT
authors: Fuhrman
authors: Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: J
authors: J
authors: Leiner
authors: Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, Virginia 22030, USA.
authors: P
authors: P
authors: Nikolić
authors: Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: G E
authors: GE
authors: Granroth
authors: Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: M B
authors: MB
authors: Stone
authors: Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: M D
authors: MD
authors: Lumsden
authors: Instrument Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: L
authors: L
authors: DeBeer-Schmitt
authors: National Research Centre "Kurchatov Institute," 123182 Moscow, Russia and National Research Nuclear University "MEPhI," 115409 Moscow, Russia.
authors: P A
authors: PA
authors: Alekseev
authors: Laboratoire Léon Brillouin, CEA-CNRS, CEA/Saclay, 91191 Gif sur Yvette, France.
authors: J-M
authors: JM
authors: Mignot
authors: Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors: S M
authors: SM
authors: Koohpayeh
authors: Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors: P
authors: P
authors: Cottingham
authors: Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors: W Adam
authors: WA
authors: Phelan
authors: Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Chemistry, Princeton University, Princeton, New Jersey 08540, USA.
authors: L
authors: L
authors: Schoop
authors: Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors: T M
authors: TM
authors: McQueen
authors: Institute for Quantum Matter and Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA and Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors: C
authors: C
authors: Broholm