Topological insulators are a class of solids in which the non-trivial inverted bulk band structure gives rise to metallic surface states that are robust against impurity scattering. In this article, differential magnetometry was used to probe spin rotation in the 3D topological material family (Bi2Se3, Bi2Te3 and Sb2Te3). They reported a paramagnetic singularity in the magnetic susceptibility at low magnetic fields that persists up to room temperature, and which we demonstrate to arise from the surfaces of the samples.
L. Zhao et al., Nature Materials 13, 580–585 (May 2014)
