Abstract
Tight-binding electrons on the honeycomb lattice are studied where nearest-neighbor hoppings in the three directions are , , and , respectively. For the isotropic case—namely, for —two zero modes exist where the energy dispersions at the vanishing points are linear in momentum . Positions of zero modes move in the momentum space as , , and are varied. It is shown that zero modes exist if . The density of states near a zero mode is proportional to but it is propotional to at the boundary of this condition
- Received 16 April 2006
DOI:https://doi.org/10.1103/PhysRevB.74.033413
©2006 American Physical Society