Tunable charge donation and spin polarization of metal adsorbates on graphene using applied electric field

TL;DR

This study uses DFT-based STS simulations to explore how metal adsorbates on graphene influence charge and spin states, demonstrating tunability via external electric fields with implications for nanoelectronic applications.

Contribution

It provides new insights into the microscopic charge and spin polarization mechanisms of metal atoms on graphene and shows how external electric fields can modulate these properties.

Findings

Cs atom fully ionized with band bending features

Charge and magnetic states of Ba and La are complex due to hybridization

External electric fields alter charge donation and spin moments

Abstract

Metal atoms on graphene, when ionized, can act as a point charge impurity to probe a charge response of graphene with the Dirac cone band structure. To understand the microscopic physics of the metal-atom-induced charge and spin polarization in graphene, we present scanning tunneling spectroscopy (STS) simulations based on density functional theory calculations. We find that a Cs atom on graphene are fully ionized with a significant band bending feature in the STS, whereas the charge and magnetic states of Ba and La atoms on graphene appear to be complicated due to orbital hybridization and Coulomb interaction. By applying an external electric field, we observe changes in charge donations and spin magnetic moments of the metal adsorbates on graphene.