Uniformity of the pseudomagnetic field in strained graphene

TL;DR

This study investigates how the pseudomagnetic field in strained graphene varies with orientation, demonstrating near-uniformity within a specific region and its implications for experimental detection.

Contribution

It provides a simulation-based analysis of pseudomagnetic field uniformity in strained graphene depending on lattice orientation and strain direction.

Findings

Maximum pseudomagnetic field of 1.2 T at 3.5% strain

Uniformity within a 520 nm diameter region

Optimal field strength when strain is perpendicular to armchair direction

Abstract

We present a study on the uniformity of the pseudomagnetic field in graphene as a function of the relative orientation between the graphene lattice and straining directions. For this, we strained a regular micron-sized graphene hexagon by deforming it symmetrically by displacing three of its edges. By simulations, we found that the pseudomagnetic field is strongest if the strain is applied perpendicular to the armchair direction of graphene. For a hexagon with a side length of 1 ${\rm \mu}$m, the pseudomagnetic field has a maximum of 1.2 T for an applied strain of 3.5% and it is uniform (variance $< 1$%) within a circle with a diameter of $\sim 520$ nm. This diameter is on the order of the typical diameter of the laser spot in a state-of-the-art confocal Raman spectroscopy setup, which suggests that observing the pseudomagnetic field in measurements of shifted magneto-phonon resonance is feasible.