Epitaxial graphene integrated with a monolayer magnet

TL;DR

This study demonstrates the integration of epitaxial graphene with a 2D magnetic material via Eu intercalation, revealing magnetic properties and spintronic potential without disrupting graphene's electronic structure.

Contribution

It reports the synthesis and analysis of a novel heterostructure combining epitaxial graphene with a 2D magnet, advancing spintronics applications.

Findings

Revealed easy-plane 2D magnetism with controllable transition temperature.

Observed negative magnetoresistance and anomalous Hall effect indicating spin polarization.

Maintained graphene's electronic properties post-intercalation, evidenced by quantum oscillations.

Abstract

Imprinting magnetism into graphene makes an important step to its applications in spintronics. An actively explored approach is proximity coupling of graphene to a 2D magnet. In these endeavors, the use of epitaxial graphene may bring significant advantages due to its superiority over the exfoliated counterpart and natural integration with the substrate but the problem of attaining magnetism persists. Here, we report synthesis and analysis of a heterostructure coupling epitaxial graphene with a regular lattice of magnetic atoms formed by Eu intercalation. The magnetization measurements reveal easy-plane 2D magnetism in the material, with the transition temperature controlled by low magnetic fields. The emerging negative magnetoresistance and anomalous Hall effect point at spin polarization of the carriers in graphene. In the paramagnetic phase, the magnetoresistance in graphene exhibits critical exponential behavior of the induced magnetic state. The intercalation does not compromise the parental electronic structure - quantum oscillations in the resistivity manifest low-mass carriers in graphene. The results are set against those for an isostructural material based on intercalated nonmagnetic Sr. Overall, the study expands the family of 2D magnets and establishes a prospective material for graphene-based spintronics.