Graphene with geometrically induced vorticity

Pachos, Jiannis K.; Stone, Michael; Temme, Kristan

Graphene with geometrically induced vorticity

Authors

Pachos, Jiannis K.

Stone, Michael

Temme, Kristan

Description

At half filling, the electronic structure of graphene can be modelled 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 Kekule modulation of the hopping matrix elements can correspond to a non-real Higgs field with non-trivial vorticity. This provides a natural setting for fractionally charged vortices with localized zero modes. For fullerene-like molecules we employ the index theorem to demonstrate the existence of six low-lying states that do not depend strongly on the Kekule-induced mass gap.
4 pages, 3 figures, to appear in PRL