2016/12/12 by Lin Jiao, Sahana Rößler, D. J. Kim +4
Physics and Astronomy · #Advanced Condensed Matter Physics #Band gap #Condensed matter physics #Electronic structure #Impurity #Kondo effect #Kondo insulator #Materials science #Physics #Quantum mechanics #Quantum tunnelling #Rare-earth and actinide compounds #Scanning tunneling microscope #Scanning tunneling spectroscopy #Spectroscopy #Topological Materials and Phenomena #Topological insulator #Valence (chemistry) #cond-mat.str-el
paper · pdf · doi:10.1038/ncomms13762
published as Nature Commun. 7 (2016) 13762
openalex publication_date 2016/12/12 · arxiv created 2017/01/11 · arxiv updated 2017/01/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract Topological insulators give rise to exquisite electronic properties because of their spin-momentum locked Dirac-cone-like band structure. Recently, it has been suggested that the required opposite parities between valence and conduction band along with strong spin-orbit coupling can be realized in correlated materials. Particularly, SmB 6 has been proposed as candidate material for a topological Kondo insulator. Here we observe, by utilizing scanning tunnelling microscopy and spectroscopy down to 0.35 K, several states within the hybridization gap of about ±20 meV on well characterized (001) surfaces of SmB 6 . The spectroscopic response to impurities and magnetic fields allows to distinguish between dominating bulk and surface contributions to these states. The surface contributions develop particularly strongly below about 7 K, which can be understood in terms of a suppressed Kondo effect at the surface. Our high-resolution data provide insight into the electronic structure of SmB 6 , which reconciles many current discrepancies on this compound.