title: Surface-dominated conduction up to 240 K in the Kondo insulator SmB6under strain.
abstract: SmB6is 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. ), limiting its scientific investigation and device application. Here, we report the enhancement of T∗in SmB6under 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 SmB6films via substrate in potential device applications.
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
authors.forename: A
authors.initials: A
authors.lastname: Stern
authors.affiliation: Department of Physics, Kent State University, Kent, Ohio 44242, USA.
authors.forename: M
authors.initials: M
authors.lastname: Dzero
authors.affiliation: Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: V M
authors.initials: VM
authors.lastname: Galitski
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Fisk
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
authors.forename: J
authors.initials: J
authors.lastname: Xia