Quantum Transport in Graphene in Presence of Strain-Induced Pseudo-Landau Levels

TL;DR

This paper investigates how strain-induced pseudomagnetic fields in graphene affect electron transport, revealing unique localization phenomena and potential for tunable metal-insulator transitions.

Contribution

It provides the first detailed numerical analysis of transport in disordered graphene with strain-induced pseudomagnetic Landau levels, highlighting anomalous behaviors near the zeroth pLL.

Findings

Pseudomagnetic fields up to hundreds of Tesla significantly alter scattering.

Near the zeroth pLL, mean free paths increase with disorder, contrary to expectations.

Strain-induced pseudomagnetic fields can enable reversible control of metal-insulator transitions.

Abstract

We report on mesoscopic transport fingerprints in disordered graphene caused by strain-field induced pseudomagnetic Landau levels (pLLs). Efficient numerical real space calculations of the Kubo formula are performed for an ordered network of nanobubbles in graphene, creating pseudomagnetic fields up to several hundreds of Tesla, values inaccessible by real magnetic fields. Strain-induced pLLs yield enhanced scattering effects across the energy spectrum resulting in lower mean free path and enhanced localization effects. In the vicinity of the zeroth order pLL, we demonstrate an anomalous transport regime, where the mean free paths increases with disorder. We attribute this puzzling behavior to the low-energy sub-lattice polarization induced by the zeroth order pLL, which is unique to pseudomagnetic fields preserving time-reversal symmetry. These results, combined with the experimental feasibility of reversible deformation fields, open the way to tailor a metal-insulator transition driven by pseudomagnetic fields.