Magnetic and Electronic Properties of Metal-Atom Adsorbed Graphene

TL;DR

This study uses first principles calculations to explore how adsorbing metal atoms on graphene affects its magnetic and electronic properties, revealing potential for quantum anomalous Hall and quantum valley Hall effects.

Contribution

It provides a systematic analysis of how different metal adatoms influence graphene's electronic structure, highlighting the emergence of topologically nontrivial gaps.

Findings

Transition metals induce exchange fields and Rashba spin-orbit coupling.

Noble metals favor top adsorption sites and induce valley Hall effects.

Different adatoms lead to distinct nontrivial bulk gaps.

Abstract

We systematically investigate the magnetic and electronic properties of graphene adsorbed with diluted 3d-transition and noble metal atoms using first principles calculation methods. We find that most transition metal atoms (i.e. Sc, Ti, V, Mn, Fe) favor the hollow adsorption site, and the interaction between magnetic adatoms and \pi-orbital of graphene induces sizable exchange field and Rashba spin-orbit coupling, which together open a nontrivial bulk gap near the Dirac points leading to the quantum-anomalous Hall effect. We also find that the noble metal atoms (i.e. Cu, Ag, Au) prefer the top adsorption site, and the dominant inequality of the AB sublattice potential opens another kind of nontrivial bulk gap exhibiting the quantum-valley Hall effect.