Ferromagnetism and superconductivity with possible $p+ip$ pairing symmetry in partially hydrogenated graphene

Abstract

By means of first-principles calculations, we predict two new types of partially hydrogenated graphene systems: C${}_6$H${}_1$ and C${}_6$H${}_5$, which are shown to be ferromagnetic (FM) semimetal and FM narrow-gap semiconductor, respectively. When properly doped, the Fermi surface of the two systems consists of an electron pocket or six hole patches in the first Brillouin zone with completely spin-polarized charge carries. If superconductivity exists in these systems, the stable pairing symmetries are shown to be $p+ip$ for electron doped case, and anisotropic $p+ip$ for hole doped case. The predicted systems may provide fascinating platforms for studying the novel properties of ferromagnetism and triplet-pairing superconductivity as well as two-dimensional spintronics.