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

TL;DR

This paper explores the potential for unconventional superconductivity and spin excitations in heavily overdoped monolayer graphene, drawing parallels with cuprate superconductors and suggesting it as a new research platform.

Contribution

It provides a theoretical analysis of spin excitations and superconductivity in doped monolayer graphene near the Van Hove singularity, highlighting its similarities to cuprates.

Findings

Static spin-density-wave state is favored at Van Hove doping.

Superconductivity may emerge with further doping.

Spin excitation features resemble those in cuprate superconductors.

Abstract

Recently it was reported experimentally that the monolayer graphene can be doped to beyond the Van Hove singularity. 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. Thus we have proposed an exciting possibility, namely, the heavily overdoped monolayer graphene can become a novel platform to study the unconventional superconductivity.