Spin excitations in the heavily overdoped monolayer graphene superconductor: An analog to the cuprates

Recently it was reported experimentally that the monolayer graphene can be heavily overdoped to beyond the Van Hove regime. We study theoretically the possible superconductivity and the corresponding spin excitations of the monolayer graphene in this doping region. A static spin-density-wave state is favorable due to the nested Fermi surface as the Fermi level is doped to the Van Hove singularity point. Superconductivity may be realized upon further doping. The spin excitations in the superconducting state are studied theoretically based on the random phase approximation. The overall features are qualitatively the same with those in cuprate superconductors due to similar Fermi surface topologies of these two families of materials. Thus we have proposed an exciting possibility, namely, the recently realized beyond-Van Hove graphene is a cuprate analog and can become a novel platform to study the unconventional superconductivity.

Automated summary

Recent experimental reports suggest that heavily overdoped monolayer graphene may exhibit superconductivity beyond the Van Hove regime. Theoretical studies have shown that a static spin-density-wave state could be favored in this doping region due to the nested Fermi surface at the Van Hove singularity point. Further research is needed to explore the possibility of spin excitations in the superconducting state.