Abstract
A direct signature of electron transport at the metallic surface of a topological insulator is the Aharonov-Bohm oscillation observed in a recent study of nanowires [Peng et al., Nature Mater. 9, 225 (2010)] where conductance was found to oscillate as a function of magnetic flux through the wire, with a period of one flux quantum and maximum conductance at zero flux. This seemingly agrees neither with diffusive theory, which would predict a period of half a flux quantum, nor with ballistic theory, which in the simplest form predicts a period of but a minimum at zero flux due to a nontrivial Berry phase in topological insulators. We show how and flux oscillations of the conductance depend on doping and disorder strength, provide a possible explanation for the experiments, and discuss further experiments that could verify the theory.
- Received 14 July 2010
DOI:https://doi.org/10.1103/PhysRevLett.105.156803
© 2010 The American Physical Society