2016/07/31 by Abraham C. Stern, A. Stern, Maxim Dzero +6 · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Composite material #Condensed matter physics #Electron #Kondo effect #Kondo insulator #Limiting #Materials science #Physics #Quantum mechanics #Rare-earth and actinide compounds #Strain (injury) #Thermal conduction #Topological Materials and Phenomena #Topological insulator #Valence (chemistry) #cond-mat.mes-hall #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1038/nmat4888
published as Nature Materials (2017), · to appear in Nature Materials
openalex created_date 2016/09/16 · arxiv created 2017/02/23 · openalex publication_date 2017/04/03 · arxiv updated 2017/04/05 · openalex updated_date 2026/08/06
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 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 indued in epitaxial SmB6 films via substrate in potential device applications.