Topological surface state in the Kondo Insulator Samarium Hexaboride

Understand

Strongly correlated electron systems show many exotic properties such as unconventional superconductity, quantum criticality, and Kondo insulating behavior.

• In addition, the Kondo insulator SmB6 has been predicted theoretically to be a 3D topological insulator with a metallic surface state.
• We report here transport measurements on doped SmB6, which show that ~3% magnetic and non-magnetic dopants in SmB6 exhibit clearly contrasting behavior, evidence that the metallic surface state is only destroyed when time reversal symmetry is broken.
• We find as well a quantum percolation limit of impurity concentration which transform the topological insulator into a conventional band insulator by forming impurity band.