Interplay of Superconductivity, Ferromagnetism, and Half-Metallicity in Gated Single-Layer g‑C3N4

TL;DR

This paper explores how doping a carbon nitride material can lead to unique electronic states like superconductivity and magnetism.

Contribution

The study reveals a novel platform for strongly correlated states in gated 2D systems with lone pairs.

Findings

Field-effect hole doping in g-C3N4 depletes lone pairs and unveils correlated states.

Superconducting, half-metallic, and ferromagnetic phases coexist in the material.

These effects occur without transition metal ions and at low charging levels.

Abstract

Graphitic carbon nitride (g-C3N4) hosts lone
pairs arising from broken carbon–nitrogen bonds in its heptazine
structure. These strongly localized and weakly hybridized states form
ultraflat bands, potentially leading to correlated states when doped.
Using first-principles calculations, we show that field-effect hole
doping in single-layer g-C3N4 depletes these
lone pairs, unveiling a rich phase diagram with a complex interplay
of superconducting, half-metallic, and insulating ferromagnetic phases,
even at very low charging and in the absence of transition metal ions.
Our work highlights gated two-dimensional systems hosting lone pairs
as a novel platform for strongly correlated states.

Figures