Surface Hall Effect and Nonlocal Transport in SmB(6): Evidence for Surface Conduction

A topological insulator (TI) is an unusual quantum state in which the insulating bulk is topologically distinct from vacuum, resulting in a unique metallic surface that is robust against time-reversal invariant perturbations. The surface transport, however, remains difficult to isolate from the bulk conduction in most existing TI crystals (particularly Bi(2)Se(3), Bi(2)Te(3) and Sb(2)Te(3)) due to impurity caused bulk conduction. We report in large crystals of topological Kondo insulator (TKI) candidate material SmB(6) the thickness-independent surface Hall effects and non-local transport, which persist after various surface perturbations. These results serve as proof that at low temperatures SmB6 has a metallic surface that surrounds an insulating bulk, paving the way for transport studies of the surface state in this proposed TKI material.