Kekulé superconductivity and antiferromagnetism on the graphene lattice

Abstract

We investigate superconducting order in the extended Hubbard model on the two-dimensional graphene lattice using the variational cluster approximation (VCA) with an exact diagonalization solver at zero temperature. Building on the results of Ref.$[1]$, which identified triplet $p$- and $p+ip$-wave superconductivity as the most favored pairing symmetries in that model, we place uniform SC solutions in competition with the proposed nonuniform Kekulé ($p+ip$-K) superconducting pattern proposed in Ref.$[2]$. We find that the $p+ip$-K solution is in fact the most favored pairing in most of the phase diagram. In addition, we show that antiferromagnetism can co-exist with the $p+ip$-K state and that both orders are enhanced by their coexistence.

6 pages, 7 figures

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• Cooperon condensation and intra-valley pairing states in honeycomb Dirac systems
• A Hybrid-Monte-Carlo study of monolayer graphene with partially screened Coulomb interactions at finite spin density
• Non-centrosymmetric superconductors on honeycomb lattice
• Synthesis of Majorana mass terms in low-energy quantum systems
• Spiral magnetism and chiral superconductivity in Kondo-Hubbard triangular lattice model