  We propose a chiral symmetry restoration mechanism in monolayer graphene, in
analogy with the strongly coupled gauge theory. The chiral (sublattice)
symmetry of graphene, which is spontaneously broken under the effectively
strong Coulomb interaction, is restored by introducing the Kekule-patterned
lattice distortion externally. Such a phase transition is investigated
analytically by the lattice gauge theory model with the original honeycomb
lattice structure. We discuss the relation between the chiral phase transition
and the spectral gap amplitude.
