Quantum oscillations in a topological insulator Bi2Te2Se with large bulk resistivity (6 Ω cm)

We report the observation of prominent Shubnikov-de Haas oscillations in a Topological Insulator, Bi2Te2Se, with large bulk resistivity (6 Omega cm at 4 K). By fitting the SdH oscillations, we infer a large metallicity parameter k(F)l=41, with a surface mobility (mu(s) similar to 2800 cm(2)/V s) much larger than the bulk mobility (mu(b) similar to 50 cm(2)/V s). The plot of the index fields B-v vs. filling factor v shows a 1/2-shift, consistent with massless, Dirac states. (C) 2011 Elsevier B.V. All rights reserved.