Suppression of magnetic excitations near the surface of the topological Kondo insulator SmB6

Abstract

We present a detailed investigation of the temperature and depth dependence of the magnetic properties of 3D topological Kondo insulator SmB6 , in particular near its surface. We find that local magnetic field fluctuations detected in the bulk are suppressed rapidly with decreasing depths, disappearing almost completely at the surface. We attribute the magnetic excitations to spin excitons in bulk SmB6 , which produce local magnetic fields of about ~1.8 mT fluctuating on a time scale of ~60 ns. We find that the excitonic fluctuations are suppressed when approaching the surface on a length scale of 40-90 nm, accompanied by a small enhancement in static magnetic fields. We associate this length scale to the size of the excitonic state.

5 pages, 5 figures, accepted for publication as a Rapid Communication in Phys. Rev. B

References in corpus (6)

• Correlated Topological Insulators with Mixed Valence
• Direct observation of the spin texture in strongly correlated SmB6 as evidence of the topological Kondo insulator
• Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
• Interaction Driven Subgap Spin Exciton in the Kondo Insulator SmB6
• Anomalous 3D bulk AC conduction within the Kondo gap of SmB${}_6$ single crystals
• Low-temperature magnetic fluctuations in the Kondo insulator SmB6

Cited by in corpus (4)

• Bulk Rotational Symmetry Breaking in Kondo Insulator SmB6
• Slow crystalline electric field fluctuations in the Kondo lattice SmB${}_6$
• Second and third harmonics generation by coherent sub-THz radiation at induced Lifshitz transitions in gapped bilayer graphene
• Direct measurement of a remnant Fermi surface in SmB6