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Phys. Rev. B 80, 155305 (2009) [12 pages]

Exact solution for bulk-edge coupling in the non-Abelian ν=5/2 quantum Hall interferometer

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Bernd Rosenow1, Bertrand I. Halperin2, Steven H. Simon3, and Ady Stern4
1Max-Planck-Institute for Solid State Research, Heisenbergstr. 1, D-70569 Stuttgart, Germany
2Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA
3Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, United Kingdom
4Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel

Received 3 June 2009; published 5 October 2009

It has been predicted that the phase sensitive part of the current through a non-Abelian ν=5/2 quantum Hall Fabry-Perot interferometer will depend on the number of localized charged e/4 quasiparticles (QPs) inside the interferometer cell. In the limit where all QPs are far from the edge, the leading contribution to the interference current is predicted to be absent if the number of enclosed QPs is odd and present otherwise, as a consequence of the non-Abelian QP statistics. The situation is more complicated, however, if a localized QP is close enough to the boundary so that it can exchange a Majorana fermion with the edge via a tunneling process. Here, we derive an exact solution for the dependence of the interference current on the coupling strength for this tunneling process, and confirm a previous prediction that for sufficiently strong coupling, the localized QP is effectively incorporated in the edge and no longer affects the interference pattern. We confirm that the dimensionless coupling strength can be tuned by the source-drain voltage, and we find that not only does the magnitude of the even-odd effect change with the strength of bulk-edge coupling, but in addition, there is a universal shift in the interference phase as a function of coupling strength. Some implications for experiments are discussed at the end.

© 2009 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevB.80.155305
DOI:
10.1103/PhysRevB.80.155305
PACS:
73.43.Cd, 73.43.Jn