Multifractal wave functions of charge carriers in graphene with folded deformations, ripples or uniaxial flexural modes: analogies to the quantum Hall effect under random pseudomagnetic fields

TL;DR

This paper investigates how uniaxial deformations in graphene create pseudomagnetic fields, leading to multifractal zero-energy wavefunctions and effects analogous to the quantum Hall effect, with implications for tailoring electronic properties.

Contribution

It introduces a method to model uniaxial deformations as pseudomagnetic fields and analyzes their impact on wavefunctions and electronic behavior in graphene.

Findings

Zero energy modes are multifractal under random deformations.

Density of states follows a power law in disordered graphene.

Strong Aharonov-Bohm pseudo-effect observed in deformed graphene.

Abstract

The electronic behavior in graphene under arbitrary uniaxial deformations, such as foldings or flexural fields is studied by including in the Dirac equation pseudoelectromagnetic fields. General foldings are thus studied by showing that uniaxial deformations can be considered pseudomagnetic fields in the Coulomb gauge norm. This allows to give an expression for the Fermi (zero) energy modes wavefunctions. For random deformations, contact is made with previous works on the quantum Hall effect under random magnetic fields, showing that the density of states has a power law behavior and that the zero energy modes wavefunctions are multifractal. This hints at an unusual electron velocity distribution. Also, it is shown that a strong Aharonov-Bohm pseudo-effect is produced. For more general non-uniaxial general flexural strain, it is not possible to use the Coulomb gauge. The results presented here helps to tailor-made graphene uniaxial deformations to achieve specific wavefunctions.