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arXiv · 1702.02198

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

K. Akintola·A. Pal·M. Potma·S. R. Saha·X. F. Wang·J. Paglione·J. E. Sonier
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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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K. Akintola, A. Pal, M. Potma, S. R. Saha, X. F. Wang, J. Paglione, J. E. Sonier. 2017-02-07. Quantum spin fluctuations in the bulk insulating state of pure and Fe-doped SmB6. https://doi.org/10.1103/physrevb.95.245107

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