Abstract
The low-energy electronic spectra of rotationally faulted graphene bilayers are studied using a long-wavelength theory applicable to general commensurate fault angles. Lattice commensuration requires low-energy electronic coherence across a fault and pre-empts massless Dirac behavior near the neutrality point. Sublattice exchange symmetry distinguishes two families of commensurate faults that have distinct low-energy spectra which can be interpreted as energy-renormalized forms of the spectra for the limiting Bernal and stacked structures. Sublattice-symmetric faults are generically fully gapped systems due to a pseudospin-orbit coupling appearing in their effective low-energy Hamiltonians.
- Received 22 March 2010
DOI:https://doi.org/10.1103/PhysRevB.81.161405
©2010 American Physical Society