Quantum spin fluctuations in the bulk insulating state of pure and Fe-doped SmB6

Abstract

The intermediate-valence compound SmB6 is a well-known Kondo insulator, in which hybridization of itinerant 5d electrons with localized 4f electrons leads to a transition from metallic to insulating behavior at low temperatures. Recent studies suggest that SmB6 is a topological insulator, with topological metallic surface states emerging from a fully insulating hybridized bulk band structure. Here we locally probe the bulk magnetic properties of pure and 0.5 % Fe-doped SmB6 by muon spin rotation/relaxation methods. Below 6 K the Fe impurity induces simultaneous changes in the bulk local magnetism and the electrical conductivity. In the low-temperature insulating bulk state we observe a temperature-independent dynamic relaxation rate indicative of low-lying magnetic excitations driven primarily by quantum fluctuations.

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• Low-temperature magnetic fluctuations in the Kondo insulator SmB6
• Incomplete Protection of the Surface Weyl Cones of the Kondo Insulator SmB${}_6$: Spin Exciton Scattering
• Suppression of magnetic excitations near the surface of the topological Kondo insulator SmB6
• Surface and bulk components of electrical conductivity in the (presumably special topological) Kondo insulator SmB6 at lowest temperatures

Cited by in corpus (8)

• Imaging emergent heavy Dirac fermions of a topological Kondo insulator
• Consistency between ARPES and STM measurements on SmB${}_6$
• Field-dependent heat transport in the Kondo insulator SmB6 : phonons scattered by magnetic impurities
• Visualizing the atomic-scale origin of metallic behavior in Kondo insulators
• Valence and Spin fluctuations in Mn-doped ferroelectric BaTiO3
• Intrinsic Low-Temperature Magnetism in SmB6
• An STM perspective on hexaborides: Surface states of the Kondo insulator SmB${}_6$
• Screened moments in a Kondo insulator