Strained graphene Hall bar

TL;DR

This study investigates how a Gaussian bump-induced strain affects the magnetic field-dependent transport properties of a graphene Hall bar, revealing characteristic features and potential for bump size estimation through numerical simulations.

Contribution

It provides a comparative analysis of classical and quantum transport theories on strained graphene, highlighting bump-assisted scattering effects and Landau level oscillations.

Findings

Decrease in bend resistance around zero magnetic field

Occurrence of side-peaks in bend resistance

Quantum oscillations due to Landau level population changes

Abstract

The effects of strain, induced by a Gaussian bump, on the magnetic field dependent transport properties of a graphene Hall bar are investigated. The numerical simulations are performed using both classical and quantum mechanical transport theory and we found that both approaches exhibit similar characteristic features. The effects of the Gaussian bump are manifested by a decrease of the bend resistance, $R_B$, around zero-magnetic field and the occurrence of side-peaks in $R_B$. These features are explained as a consequence of bump-assisted scattering of electrons towards different terminals of the Hall bar. Using these features we are able to give an estimate of the size of the bump. Additional oscillations in $R_B$ are found in the quantum description that are due to the population/depopulation of Landau levels. The bump has a minor influence on the Hall resistance even for very high values of the pseudo-magnetic field. When the bump is placed outside the center of the Hall bar valley polarized electrons can be collected in the leads.