Direct link between bulk thermodynamic measurements and surface conduction in SmB6

摘要: Topological insulators are materials characterized by dissipationless, spin-polarized surface states resulting from non-trivial band topologies. Recent theoretical models and experiments suggest that SmB6 is the first topological Kondo insulator, in which topologically structure results electron-electron interactions via hybridization. Here, we report conductivity of increases systematically with bulk carbon content. Further, addition linked to an increase n-type carriers, larger low temperature electronic contributions specific heat a characteristic scale T*=17K, broadening crossover insulating state. Additionally, X-ray absorption spectroscopy shows change Sm valence at surface. Our provide direct link between thermodynamic state properties SmB6, demonstrate both phonon dynamics chemistry must be elucidated order resolve whether insulator.