Giant Nonlocality near the Dirac Point in Graphene

TL;DR

This paper reports large nonlocal electrical responses near the Dirac point in graphene, observable at low magnetic fields and room temperature, attributed to long-range flavor currents affecting magnetotransport.

Contribution

It demonstrates significant nonlocality in graphene near the Dirac point caused by flavor currents, a novel observation in low magnetic fields and at room temperature.

Findings

Large nonlocal response observed near the Dirac point

Nonlocality persists up to room temperature

Attribution to long-range flavor currents

Abstract

Transport measurements have been a powerful tool for uncovering new electronic phenomena in graphene. We report nonlocal measurements performed in the Hall bar geometry with voltage probes far away from the classical path of charge flow. We observe a large nonlocal response near the Dirac point in fields as low as 0.1T, which persists up to room temperature. The nonlocality is consistent with the long-range flavor currents induced by lifting of spin/valley degeneracy. The effect is expected to contribute strongly to all magnetotransport phenomena near the neutrality point.