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

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

 Kalon Gopinadhan, Young Jun Shin, Rashid Jalil, Thirumalai Venkatesan, Andre K. Geim, Antonio H. Castro Neto & Hyunsoo Yan

 Nature Communications 6, Article number: 8337 doi:10.1038/ncomms9337

Received 19 December 2014 Accepted 11 August 2015 Published 21 September 2015

Researchers from the prestigious National University of Singapore (NUS) have successfully invented a new hybrid magnetic sensor, more sensitive than most commercially available sensors to date.

Understanding magnetoresistance, the change in electrical resistance under 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 an applied magnetic field of 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.