Reading and writing charge on graphene devices

TL;DR

This paper demonstrates a technique combining charge writing and scanning gate microscopy to map and modify local charge neutrality in graphene devices, supported by electrostatic simulations.

Contribution

It introduces a novel method for spatially controlling and mapping charge neutrality in graphene using charge writing and microscopy, validated by simulations.

Findings

Successful mapping of local charge neutrality points

Effective modification of charge neutrality via charge writing

Good agreement between experimental results and electrostatic simulations

Abstract

We use a combination of charge writing and scanning gate microscopy to map and modify the local charge neutrality point of graphene field-effect devices. We give a demonstration of the technique by writing remote charge in a thin dielectric layer over the graphene-metal interface and detecting the resulting shift in local charge neutrality point. We perform electrostatic simulations to characterize the gating effect of a realistic scanning probe tip on a graphene bilayer and find a good agreement with the experimental results.