Shubnikov–de Haas oscillations in n and p type Bi2Se3 flakes

Abstract

Shubnikov–de Haas (SdH) oscillation, describing the magnetic quantum oscillation in material resistivity at low temperatures, is recently observed in topological insulators and plays an important role in clarifying the existence of topological surface states. Here, we report the SdH oscillations observed in both n and p type Bi2Se3 flake samples. The angle dependent magneto-resistance results reveal the 2D nature of SdH oscillations and the Landau level fan diagrams exhibit π Berry phase. These indicate that the observed SdH oscillations originate from the topological surface states. Moreover, the cyclotron mass, Dingle temperature, Fermi velocity, and other parameters of the systems are deduced from the analysis of temperature dependent SdH oscillations. The obtained Fermi velocities of surface electrons and holes in Bi2Se3 show a good agreement with those found in the typical angle-resolved photoemission spectroscopy experiments. This further confirms that the topological surface electrons/holes are responsible for observed SdH oscillations.