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Ground-state degeneracy of correlated insulators with edges

Refael, Gil and Lin, Hsiu-Hau (2005) Ground-state degeneracy of correlated insulators with edges. Physical Review B, 72 (7). Art. No. 073109. ISSN 1098-0121. http://resolver.caltech.edu/CaltechAUTHORS:REFprb05

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Abstract

Using the topological flux insertion procedure, the ground-state degeneracy of an insulator on a periodic lattice with filling factor nu=p/q was found to be at least q-fold. Applying the same argument in a lattice with edges, we show that the degeneracy is modified by the additional edge density nuE associated with the open boundaries. To carry out this generalization we demonstrate how to distinguish between bulk and edge states, and follow how an edge modifies the thermodynamic limit of Oshikawa's original argument. In particular, we also demonstrate that these edge corrections may even make an insulator with integer bulk filling degenerate.


Item Type:Article
Additional Information:©2005 The American Physical Society (Received 24 June 2005; published 26 August 2005) We would like to thank Leon Balents, Matthew Fisher, Arun Paramekanti, Tami Pereg-Barnea, and particularly Masaki Oshikawa for insightful discussions. H.H.L. is grateful for support from NSC-91-2120-M-007-001 and NSC-92-2112-M-007-039. G.R. thankfully acknowledges support from NSF fund PHY99-07949.
Subject Keywords:ground states; insulating materials; topology
Record Number:CaltechAUTHORS:REFprb05
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:REFprb05
Alternative URL:http://dx.doi.org/10.1103/PhysRevB.72.073109
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7129
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:09 Jan 2007
Last Modified:26 Dec 2012 09:29

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