Programmable Extreme Pseudomagnetic Fields in Graphene by a Uniaxial Stretch

TL;DR

This paper demonstrates a simple, geometrical method to generate programmable, uniform, and extreme pseudomagnetic fields in planar graphene sheets through uniaxial stretching, enabling advanced strain engineering of 2D materials.

Contribution

It introduces a novel, shape-based approach to control pseudomagnetic fields in graphene, overcoming previous non-planar limitations and enabling large-area uniform field generation.

Findings

Achieved pseudomagnetic fields up to hundreds of Tesla.

Demonstrated uniform pseudomagnetic field distribution over large areas.

Enabled programmable strain-induced electronic property tuning.

Abstract

Many of the properties of graphene are tied to its lattice structure, allowing for tuning of charge carrier dynamics through mechanical strain. The graphene electro-mechanical coupling yields very large pseudomagnetic fields for small strain fields, up to hundreds of Tesla, which offer new scientific opportunities unattainable with ordinary laboratory magnets. Significant challenges exist in investigation of pseudomagnetic fields, limited by the non-planar graphene geometries in existing demonstrations and the lack of a viable approach to controlling the distribution and intensity of the pseudomagnetic field. Here we reveal a facile and effective mechanism to achieve programmable extreme pseudomagnetic fields with uniform distributions in a planar graphene sheet over a large area by a simple uniaxial stretch. We achieve this by patterning the planar graphene geometry and graphene-based hetero-structures with a shape function to engineer a desired strain gradient. Our method is geometrical, opening up new fertile opportunities of strain engineering of electronic properties of 2D materials in general.