title: Additional energy scale in SmB6at low-temperature.
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, SmB6has 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 SmB6. 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 SmB6, which reconciles many current discrepancies on this compound.
authors.affiliation: Max-Planck-Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Jiao
authors.affiliation: Max-Planck-Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Rößler
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Max-Planck-Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany.
authors.forename: L H
authors.initials: LH
authors.lastname: Tjeng
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Fisk
authors.affiliation: Max-Planck-Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany.|Center for Correlated Matter, Zhejiang University, Hangzhou 310058, China.|Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: F
authors.initials: F
authors.lastname: Steglich
authors.affiliation: Max-Planck-Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Wirth