Extremely large magnetoresistance in few-layer graphene/boron-nitride heterostructures

TL;DR

This study reports extraordinarily large magnetoresistance effects in few-layer graphene/boron-nitride heterostructures, highlighting their potential for magnetic sensing and thermal switching applications at room temperature.

Contribution

It reveals unprecedented large local and non-local magnetoresistance in graphene heterostructures and explains their origins, advancing understanding of magnetoresistance at the atomic scale.

Findings

Local magnetoresistance of ~2000% at 400 K

Non-local magnetoresistance of >90000% at 300 K in 9 T

Potential for graphene-based thermal switches and magnetic sensors

Abstract

Understanding magnetoresistance, the change in electrical resistance upon an external magnetic field, at the atomic level is of great interest both fundamentally and technologically. Graphene and other two-dimensional layered materials provide an unprecedented opportunity to explore magnetoresistance at its nascent stage of structural formation. Here, we report an extremely large local magnetoresistance of ~ 2,000% at 400 K and a non-local magnetoresistance of > 90,000% in 9 T at 300 K in few-layer graphene/boron-nitride heterostructures. The local magnetoresistance is understood to arise from large differential transport parameters, such as the carrier mobility, across various layers of few-layer graphene upon a normal magnetic field, whereas the non-local magnetoresistance is due to the magnetic field induced Ettingshausen-Nernst effect. Non-local magnetoresistance suggests the possibility of a graphene based gate tunable thermal switch. In addition, our results demonstrate that graphene heterostructures may be promising for magnetic field sensing applications.