Pseudo-magnetic field distribution and pseudo-Landau levels in suspended graphene flakes

TL;DR

This paper investigates how mechanical stretching of suspended graphene flakes induces pseudo-magnetic fields and pseudo-Landau levels, revealing that the aspect ratio and orientation significantly influence electronic properties and gap formation.

Contribution

It combines tight-binding and elasticity theory to analyze pseudo-magnetic fields and energy gaps in stretched graphene flakes with specific geometric configurations.

Findings

Pseudo-magnetic fields depend on flake orientation and aspect ratio.

Gapped states can form near contacts depending on geometry.

The largest gaps occur in armchair orientation with a width-to-length ratio of about 1.

Abstract

Combining the tight-binding approximation and linear elasticity theory for a planar membrane, we investigate stretching of a graphene flake assuming that two opposite edges of the sample are clamped by the contacts. We show that, depending on the aspect ratio of the flake and its orientation, gapped states may form in the membrane in the vicinity of the contacts. This gap in the pre-contact region should be biggest for the armchair orientation of the flake and width to length ratio of around 1.