Evidence of layered transport of bulk carriers in Fe-doped Bi2Se3 topological insulators

•The quantized Hall plateaus and Shubnikov de Haas oscillations in transition metal doped topological insulators are observed.•The evidence of a two-dimensional/layered transport of the bulk electrons is reported.•An obvious ferromagnetism in doped topological insulators is observed.•Care should be taken to pindown the transport of the topological SS in topological insulators.

We observe quantized Hall plateaus and Shubnikov de Haas oscillations in 10 at% Fe-doped Bi2Se3 flakes. All the features of the quantum transport coincide while normalizing the field-angle variable magnetoresistance to the perpendicular direction. The Hall step gives a specific contribution of ~1 e2/h per quintuple layer. This reveals a two-dimensional (2D) transport of the bulk electrons in the topological insulators. The crystal is demonstrated with an obvious ferromagnetism. Further evidences including a Berry phase of zero, a weak localization and a large effective mass rule out the contribution of the topological surface states (SS), suggesting that a great care should be taken to pindown the transport of the topological SS in topological insulators.