Abstract
We predict a universal midgap bound state in topological superfluids, induced by either nonmagnetic or magnetic impurities in the strong scattering limit. This universal state is similar to the lowest-energy Caroli–de Gennes–Martricon bound state in a vortex core, but is bound to localized impurities. We argue that the observation of such a universal bound state can be a clear signature for identifying topological superfluids. We theoretically examine our argument for a spin-orbit coupled ultracold atomic Fermi gas trapped in a two-dimensional harmonic potential by performing extensive self-consistent calculations within the mean-field Bogoliubov–de Gennes theory. A realistic scenario for observing a universal bound state in ultracold atoms is proposed.
- Received 21 September 2012
DOI:https://doi.org/10.1103/PhysRevLett.110.020401
© 2013 American Physical Society
Synopsis
Useful Impurities
Published 10 January 2013
Adding impurities to a topological superfluid—a predicted state of matter believed to host Majorana particles—may be the best way to prove it exists.
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