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.