An infinitely thin solenoid carrying magnetic flux Phi (a `Dirac string') inserted into an ordinary band insulator has no significant effect on the spectrum of electrons. In a strong topological insulator, remarkably, such a solenoid carries protected gapless one-dimensional fermionic modes when Phi=hc/2e. These modes are spin-filtered and represent a distinct bulk manifestation of the topologically non-trivial insulator. We establish this `wormhole' effect by both general qualitative considerations and by numerical calculations within a minimal lattice model. We also discuss the possibility of experimental observation of a closely related effect in artificially engineered nanostructures.
@article{arxiv.1002.3155,
title = {Wormhole Effect in a Strong Topological Insulator},
author = {G. Rosenberg and H. -M. Guo and M. Franz},
journal= {arXiv preprint arXiv:1002.3155},
year = {2014}
}
Comments
4 pages, 3 figures. For related work and info visit http://www.physics.ubc.ca/~franz