Domain Walls in Gapped Graphene

Gapped Domain Walls, Gapped Boundaries, and Topological Degeneracy Citation

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Gapped domain walls, as topological line defects between ð2 þ 1ÞD topologically ordered states, are examined. We pr...

Gapped domain walls, gapped boundaries, and topological degeneracy.

Gapped domain walls, as topological line defects between (2+1)D topologically ordered states, are examined. We provide simple criteria to determine the existence of gapped domain walls, which apply to both Abelian and non-Abelian topological orders. Our criteria also determine which (2+1)D topological orders must have gapless edge modes, namely, which (1+1)D global gravitational anomalies ensur...

Models for gapped boundaries and domain walls

We define a class of lattice models for two-dimensional topological phases with boundary such that both the bulk and the boundary excitations are gapped. The bulk part is constructed using a unitary tensor category C as in the Levin-Wen model, whereas the boundary is associated with a module category over C. We also consider domain walls (or defect lines) between different bulk phases. A domain...

Supercritical Coulomb Impurities in Gapped Graphene

We study the problem of Coulomb field-induced charging of the ground state in a system of 2D massive Dirac particles – gapped graphene. As in its 3D QED counterpart, the critical Coulomb coupling is renormalized to higher values, compared to the massless case. We find that in gapped graphene a novel supercritical regime is possible, where the screening charge is comparable to the impurity charg...

Optical response and excitons in gapped graphene