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.

References in corpus (5)

• Correlated Topological Insulators with Mixed Valence
• Direct observation of the spin texture in strongly correlated SmB6 as evidence of the topological Kondo insulator
• Surface Theory of a Family of Topological Kondo Insulators
• In-gap collective mode spectrum of the Topological Kondo Insulator SmB6
• Two-dimensional heavy fermions on the strongly correlated boundaries of Kondo topological insulators

Cited by in corpus (12)

• Fermi surface in the absence of a Fermi liquid in the Kondo insulator SmB${}_6$
• Excitons in topological Kondo insulators - theory of thermodynamic and transport anomalies in SmB${}_6$
• Additional energy scale in SmB${}_6$ at low temperature
• Anomalous 3D bulk AC conduction within the Kondo gap of SmB${}_6$ single crystals
• 4$f$ crystal field ground state of the strongly correlated topological insulator SmB${}_6$
• Suppression of magnetic excitations near the surface of the topological Kondo insulator SmB6
• The Effects of Spin-Excitons on the Surface States of SmB6: A Photoemission Study
• Magnetic end-states in a strongly-interacting one-dimensional topological Kondo insulator
• Planar tunneling spectroscopy of the topological Kondo insulator SmB${}_6$
• Collective modes in a Dirac insulator with short range interactions
• Screened moments in a Kondo insulator
• f-electron charge densities probed using core level non-resonant inelastic x-ray scattering