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Ground-State Degeneracy of Correlated Insulators with Edges

Gil Refael·Hsiu-Hau Lin
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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 $ν=p/q$ 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 $ν_{\mysw{E}}$ associated with the open boundaries. In particular, we demonstrate that these edge corrections may even make an insulator with integer bulk filling degenerate.

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Gil Refael, Hsiu-Hau Lin. 2004-09-28. Ground-State Degeneracy of Correlated Insulators with Edges. https://doi.org/10.1103/physrevb.72.073109

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