Abstract
At half filling, the electronic structure of graphene can be modeled by a pair of free two-dimensional Dirac fermions. We explicitly demonstrate that in the presence of a geometrically induced gauge field an everywhere-real Kekulé modulation of the hopping matrix elements can correspond to a nonreal Higgs field with nontrivial vorticity. This provides a natural setting for fractionally charged vortices with localized zero modes. For fullerenelike molecules we employ the index theorem to demonstrate the existence of six low-lying states that do not depend strongly on the Kekulé-induced mass gap.
Original language | English (US) |
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Article number | 156806 |
Journal | Physical review letters |
Volume | 100 |
Issue number | 15 |
DOIs | |
State | Published - Apr 18 2008 |
ASJC Scopus subject areas
- General Physics and Astronomy