Surface-dominated conduction up to 240 K in the Kondo insulator SmB 6 under strain

A. Stern, Maxim Dzero, V. M. Galitski, Z. Fisk, J. Xia

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27 Citations (Scopus)


SmB6 is a strongly correlated mixed-valence Kondo insulator with a newly discovered surface state, proposed to be of non-trivial topological origin. However, the surface state dominates electrical conduction only below T∗ ≈ 4 K (ref. 3), limiting its scientific investigation and device application. Here, we report the enhancement of T∗ in SmB6 under the application of tensile strain. With 0.7% tensile strain we report surface-dominated conduction at up to a temperature of 240 K, persisting even after the strain has been removed. This can be explained in the framework of strain-tuned temporal and spatial fluctuations of f-electron configurations, which might be generally applied to other mixed-valence materials. We note that this amount of strain can be induced in epitaxial SmB6 films via substrate in potential device applications.
Original languageEnglish
Pages (from-to)708-711
Number of pages4
JournalNature Materials
Issue number7
Publication statusPublished - 1 Jul 2017
Externally publishedYes

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