The Effects of Spin-Excitons on the Surface States of SmB6: A Photoemission Study

Abstract

We present the results of high-resolution valence-band photoemission spectroscopic study of SmB6 which shows evidence for a V-shaped density of states of surface origin within the bulk gap. The spectroscopy data is interpreted in terms of the existence of heavy 4f surface states, which may be useful in resolving the controversy concerning the disparate surface Fermi-surface velocities observed in experiments. Most importantly, we find that the temperature dependence of the valence-band spectrum indicates that a small feature appears at a binding energy of about -9 meV at low temperatures. We attribute this feature to a resonance caused by the spin-exciton scattering in SmB6 which destroys the protection of surface states due to time-reversal invariance and spin-momentum locking. The existence of a low-energy spin-exciton may be responsible for the scattering which suppresses the formation of coherent surface quasi-particles and the appearance of the saturation of the resistivity to temperatures much lower than the coherence temperature associated with the opening of the bulk gap.

References in corpus (30)

• Topological Kondo Insulators
• Surface electronic structure of the topological Kondo insulator candidate correlated electron system SmB6
• Low-temperature surface conduction in the Kondo insulator SmB${}_6$
• Correlated Topological Insulators with Mixed Valence
• Topological surface state in the Kondo Insulator Samarium Hexaboride
• Quantum oscillations in Kondo Insulator SmB${}_6$
• Robust Surface Hall Effect and Nonlocal Transport in SmB6: Indication for an Ideal Topological Insulator
• Observation of in-gap surface states in the Kondo insulator SmB6 by photoemission
• Unconventional Fermi surface in an insulating state
• Direct observation of the spin texture in strongly correlated SmB6 as evidence of the topological Kondo insulator
• Surface and Bulk Electronic Structure of the Strongly Correlated System SmB${}_6$ and Implications for a Topological Kondo Insulator
• Cubic Topological Kondo Insulators
• Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
• Tuning bulk and surface conduction in topological Kondo insulator SmB6
• Hybridization gap and Fano resonance in SmB${}_6$
• Kondo Breakdown in Topological Kondo Insulators
• Emergence of a coherent in-gap state in SmB6 Kondo insulator revealed by scanning tunneling spectroscopy
• Momentum-Dependent Hybridization Gap and dispersive in-gap state of The Kondo Semiconductor SmB6
• Interaction Driven Subgap Spin Exciton in the Kondo Insulator SmB6
• One-dimensional edge state transport in a topological Kondo insulator
• Kondo hybridisation and the origin of metallic states at the (001) surface of SmB6
• The energy gap of intermediate-valent SmB6 studied by point-contact spectroscopy
• Exotic Kondo crossover in a wide temperature region in the topological Kondo insulator SmB6 revealed by high-resolution ARPES
• Topological surface states interacting with bulk excitations in the Kondo insulator SmB${}_6$ revealed via planar tunneling spectroscopy
• Heavy surface state in a possible topological Kondo insulator: Magneto-thermoelectric transport on the (011)-plane of SmB${}_6$
• Breakdown of the Kondo insulating state in SmB6 by introducing Sm vacancies
• Surface and electronic structure of SmB${}_6$ through Scanning Tunneling Microscopy
• Incomplete Protection of the Surface Weyl Cones of the Kondo Insulator SmB${}_6$: Spin Exciton Scattering
• Imaging the Kondo Insulating Gap on SmB6
• Ultrafast terahertz spectroscopy study of Kondo insulating thin film SmB${}_6$: evidence for an emergent surface state

Cited by in corpus (10)

• Samarium hexaboride: A trivial surface conductor
• Exciton topology and condensation in a model quantum spin Hall insulator
• Magnetic impurities in Kondo insulators: An application to samarium hexaboride
• Intrinsic Low-Temperature Magnetism in SmB6
• Planar tunneling spectroscopy of the topological Kondo insulator SmB${}_6$
• Bulk Electronic Structure of Lanthanum Hexaboride (LaB6) by Hard X-ray Angle-Resolved Photoelectron Spectroscopy
• An STM perspective on hexaborides: Surface states of the Kondo insulator SmB${}_6$
• Topological nature of the Kondo insulator SmB${}_6$ and its sensitiveness to Sm vacancy
• 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