Abstract
is an important semiconductor thermoelectric material and a prototype topological insulator. Here we report observation of Shubnikov–de Hass oscillations accompanied by quantized Hall resistances () in highly doped -type with bulk carrier concentrations of few . Measurements under tilted magnetic fields show that the magnetotransport is 2D-like, where only the -axis component of the magnetic field controls the Landau level formation. The quantized step size in is found to scale with the sample thickness, and average per quintuple layer. We show that the observed magnetotransport features do not come from the sample surface, but arise from the bulk of the sample acting as many parallel 2D electron systems to give a multilayered quantum Hall effect. In addition to revealing a new electronic property of , our finding also has important implications for electronic transport studies of topological insulator materials.
- Received 31 July 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.216803
© 2012 American Physical Society