Global strain-induced scalar potential in graphene devices

TL;DR

This paper demonstrates how systematic mechanical strain can generate a scalar potential in graphene, affecting its electronic properties, and shows how this potential can be detected experimentally, enabling strain engineering of graphene's properties.

Contribution

It provides a method to generate and detect scalar potentials in graphene through controlled strain and transport measurements, advancing strain engineering techniques.

Findings

Scalar potential consistent with theoretical estimates

Detection of work function changes via transport experiments

Strain engineering of electronic properties demonstrated

Abstract

By mechanically distorting a crystal lattice it is possible to engineer the electronic and optical properties of a material. In graphene, one of the major effects of such a distortion is an energy shift of the Dirac point, often described as a scalar potential. We demonstrate how such a scalar potential can be generated systematically over an entire electronic device and how the resulting changes in the graphene work function can be detected in transport experiments. Combined with Raman spectroscopy, we obtain a characteristic scalar potential consistent with recent theoretical estimates. This direct evidence for a scalar potential on a macroscopic scale due to deterministically generated strain in graphene paves the way for engineering the optical and electronic properties of graphene and similar materials by using external strain.