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.

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Cited by in corpus (57)

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• Planar tunneling spectroscopy of the topological Kondo insulator SmB${}_6$
• Quantum spin fluctuations in the bulk insulating state of pure and Fe-doped SmB6
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• Universal spin wave damping in magnetic Weyl semimetals
• Theory Perspective: SCES 2016
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• Vortex states in a non-Abelian magnetic field
• Topological nature of the Kondo insulator SmB${}_6$ and its sensitiveness to Sm vacancy
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• Surface reconstruction in a tight-binding model for the topological Kondo insulator SmB6
• Topological surface states in the Kondo insulator YbB${}_{12}$ revealed via planar tunneling spectroscopy
• Spontaneous symmetry breaking and quantum Hall valley ordering on the surface of topological hexaborides
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• Surface excitations relaxation in the Kondo insulator Sm${}_{1-x}$Gd${}_x$B${}_6$
• A Mean-Field Study of Quantum Oscillations in Two-Dimensional Kondo Insulators
• Correlation Induced Magnetic Topological Phases in Mixed-Valence Compound SmB6
• A crossover from Kondo semiconductor to metallic antiferromagnet with $5d$-electron doping in CeFe${}_2$Al${}_{10}$
• Importance of orbital fluctuations for the magnetic dynamics in heavy-fermion compound SmB${}_6$
• f-electron charge densities probed using core level non-resonant inelastic x-ray scattering
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• Crystalline electric field excitations in Weyl semimetal \textit{R}AlSi (\textit{R} = Ce, Pr and Nd)
• Screened moments in a Kondo insulator