NMR Study of Electronic States of Bi2Se3

Graduate student David Nisson’s work on Bi₂Se₃ has recently been published.  This compound has attracted significant attention in the condensed matter physics community recently because of the interesting topological properties of its electrons.  The electrons on the Bi atoms experience strong spin-orbit coupling, which leads to an unusual property that emerges on the surface of this material.  In a pristine sample at low temperatures, the bulk of a crystal of Bi₂Se₃ should be insulating, but the surface electronic states remain conducting.  Not only can they carry an electrical current, but the current is spin-polarized.  Such materials are known as topological insulators.

In reality, most Bi₂Se₃ crystals contain sufficient numbers of defects and impurities that they are not insulating.  David’s work involved growing and characterizing single crystals with transport  and observing the NMR of the Bi-209 nuclei.  For more details see the following paper:  Nuclear magnetic resonance as a probe of electronic states of Bi₂Se_3.