Stoner ferromagnetic phase of a graphene in the presence of an in-plane magnetic field

TL;DR

This paper investigates how an in-plane magnetic field influences the magnetic and electronic properties of graphene, revealing a continuous Stoner transition and novel susceptibility behaviors depending on gap and density.

Contribution

It provides the first detailed analysis of the in-plane magnetic field effects on both gapless and gapped graphene within RPA, identifying conditions for a Stoner ferromagnetic phase transition.

Findings

Critical magnetic field increases as carrier density decreases in gapless graphene.

A continuous quantum magnetic phase transition (Stoner phase) is observed in doped graphene.

Novel dependencies of charge and spin susceptibilities on the in-plane magnetic field are uncovered.

Abstract

We study the effects of an in-plane magnetic field on the ground state properties of both gapless and gapped graphene sheets within Random Phase Approximation. The critical magnetic field which leads to a fully spin polarized phase increases by decreasing the carrier density at zero gap indicating that no spontaneous magnetic phase transition occurs. However, at large energy gap values it decreases by decreasing the density. We find a continuous quantum magnetic phase transition (Stoner phase) for Dirac fermions in a doped graphene sheet. Novel in-plane magnetic field dependence of the charge and spin susceptibilities are uncovered.