Near-zero modes in superconducting graphene

Abstract

Vortices in the simplest superconducting state of graphene contain very-low-energy excitations whose existence is connected to an index theorem that applies strictly to an approximate form of the relevant Bogoliubov–de Gennes equations. When Zeeman interactions are taken into account, the zero modes required by the index theorem are (slightly) displaced. Thus, the vortices acquire internal structure, which plausibly supports interesting dynamical phenomena.