A L\'evy flight for electrons in graphene: superdiffusive-to-diffusive transport transition

TL;DR

This paper investigates how circular electrostatic clusters in graphene nanoribbons induce a transition from superdiffusive Le9vy flight transport to diffusive behavior, depending on energy levels, highlighting a quantum-to-classical transition.

Contribution

It introduces an electronic Le9vy flight device in graphene and analyzes the energy-dependent transition from superdiffusive to diffusive transport regimes.

Findings

Electrostatic clusters cause a transition from Le9vy to diffusive transport with increasing energy.

Superdiffusive transport occurs at low energies near the Dirac point.

The transition is linked to chiral symmetry breaking as energy moves away from the Dirac point.

Abstract

In this work we propose an electronic L\'evy flight device, analogous to a recent optical realization. To that end, we investigate the transmission of electrons in graphene nanoribbons in the presence of circular electrostatic clusters, whose diameter follow a power-law distribution. We analyze the effect of the electrostatic clusters on the electronic transport regime of the nanoribbons, in terms of its diffusion behavior. Our numerical calculations show that the presence of circular electrostatic clusters induces a transition from L\'evy (superdiffusive) to diffusive transport as the energy increases. Furthermore, we argue that in our electronic L\'evy flight device, superdiffusive transport is an exclusive feature of the low-energy quantum regime, while diffusive transport is a feature of the semiclassical regime. Therefore, we attribute the observed transition to the chiral symmetry breaking, once the energy moves away from the Dirac point of graphene.