Incomplete Protection of the Surface Weyl Cones of the Kondo Insulator SmB${}_6$: Spin Exciton Scattering

Abstract

The compound SmB${}_6$ is a Kondo Insulator, where the lowest-energy bulk electronic excitations are spin excitons. It also has surface states that are subjected to strong spin-orbit coupling. It has been suggested that SmB${}_6$ is also a topological insulator. Here we show that, despite the absence of time-reversal symmetry breaking and the presence of strong spin-orbit coupling, the chiral spin texture of the Weyl cone is not completely protected. In particular, we show that the spin-exciton mediated scattering produces features in the surface electronic spectrum at energies separated from the surface Fermi energy by the spin-exciton energy. Despite the features being far removed from the surface Fermi energy, they are extremely temperature dependent. The temperature variation occurs over a characteristic scale determined by the dispersion of the spin exciton. The structures may be observed by electron spectroscopy at low temperatures.

7 pages, 5 figures

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• Scanning tunneling spectroscopy and surface quasiparticle interference in models for the strongly correlated topological insulators SmB6 and PuB6
• Two-dimensional heavy fermions on the strongly correlated boundaries of Kondo topological insulators
• Model Hamiltonian for topological Kondo insulator SmB6
• Many-body instabilities and mass generation in slow Dirac materials

Cited by in corpus (15)

• Anomalous 3D bulk AC conduction within the Kondo gap of SmB${}_6$ single crystals
• Topological surface states interacting with bulk excitations in the Kondo insulator SmB${}_6$ revealed via planar tunneling spectroscopy
• Surface-state spin textures and mirror Chern numbers in topological Kondo insulators
• Non-trivial surface states of samarium hexaboride at the (111) surface
• Exciton topology and condensation in a model quantum spin Hall insulator
• Hall anomaly, Quantum Oscillations and Possible Lifshitz Transitions in Kondo Insulator YbB${}_{12}$: Evidence for Unconventional Charge Transport
• The Effects of Spin-Excitons on the Surface States of SmB6: A Photoemission Study
• Intrinsic Low-Temperature Magnetism in SmB6
• Planar tunneling spectroscopy of the topological Kondo insulator SmB${}_6$
• Quantum spin fluctuations in the bulk insulating state of pure and Fe-doped SmB6
• Universal properties of the near-gap spectra of SmB6: dynamical mean-field calculations and photoemission experiments
• Topological nature of the Kondo insulator SmB${}_6$ and its sensitiveness to Sm vacancy
• An STM perspective on hexaborides: Surface states of the Kondo insulator SmB${}_6$
• Topological surface states in the Kondo insulator YbB${}_{12}$ revealed via planar tunneling spectroscopy
• The role of the short range magnetic correlations on the gap opening of the topological Kondo insulators