Atomic Control of Strain in Freestanding Graphene

TL;DR

This paper introduces a novel experimental method using scanning tunneling spectroscopy to precisely control and image freestanding graphene at the atomic scale, revealing large corrugations and enabling strain-induced pseudo-magnetic fields.

Contribution

The study presents a new technique for reversible, atomic-scale control of strain in freestanding graphene using constant-current STM, with high-resolution imaging of strain effects.

Findings

Achieved controllable strain up to 35 nm in graphene membranes.

Observed atomic-scale corrugations 20 times larger than electronic corrugation.

Demonstrated potential for creating pseudo-magnetic fields via strain.

Abstract

In this study, we describe a new experimental approach based on constant-current scanning tunneling spectroscopy to controllably and reversibly pull freestanding graphene membranes up to 35 nm from their equilibrium height. In addition, we present scanning tunneling microscopy (STM) images of freestanding graphene membranes with atomic resolution. Atomic-scale corrugation amplitudes 20 times larger than the STM electronic corrugation for graphene on a substrate were observed. The freestanding graphene membrane responds to a local attractive force created at the STM tip as a highly-conductive yet flexible grounding plane with an elastic restoring force. We indicate possible applications of our method in the controlled creation of pseudo-magnetic fields by strain on single-layer graphene.