Nuclear magnetic resonance as a probe of electronic states of Bi2Se3.

We present magnetotransport and 209Bi nuclear magnetic resonance (NMR) data on a series of single crystals of Bi2Se3, Bi2Te2Se, and CuxBi2Se3 with varying carrier concentrationn. The Knight shift of the bulk nuclei is strongly correlated with the carrier concentration via a hyperfine coupling of 27 μeV, which may have important consequences for scattering of the protected surface states. Surprisingly we find that the NMR linewidths and the spin-lattice relaxation rate appear to be dominated by the presence of localized spins, which may be related to the presence of Se vacancies. [ABSTRACT FROM AUTHOR]