Singular elastic strains and magnetoconductance of suspended graphene

TL;DR

This paper investigates how elastic strains in suspended graphene induce effective magnetic fields that affect quantum Hall conductance, revealing strain-induced backscattering effects that disrupt quantization.

Contribution

It demonstrates the impact of elastic strain-induced effective magnetic fields on magnetoconductance in suspended graphene, highlighting a novel strain-related mechanism affecting quantum Hall effects.

Findings

Elastic strains create effective magnetic fields up to a few Tesla.

Strain-induced fields cause backscattering of chiral edge channels.

Quantized conductance plateaus can be destroyed by strain effects.

Abstract

Graphene membranes suspended off electric contacts or other rigid supports are prone to elastic strain, which is concentrated at the edges and corners of the samples. Such a strain leads to an algebraically varying effective magnetic field that can reach a few Tesla in sub-micron wide flakes. In the quantum Hall regime the interplay of the effective and the physical magnetic fields causes backscattering of the chiral edge channels, which can destroy the quantized conductance plateaus.