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

We report the observation of prominent Shubnikov–de Haas oscillations in a Topological Insulator, Bi2Te2Se, with large bulk resistivity (6Ωcm at 4 K). By fitting the SdH oscillations, we infer a large metallicity parameter kFℓkFℓ=41, with a surface mobility (μs∼2800cm2/Vs) much larger than the bulk mobility (μb∼50cm2/Vs). The plot of the index fields BνBν vs. filling factor νν shows a 12-shift, consistent with massless, Dirac states.