High magnetoresistance at room temperature in p-i-n graphene nanoribbons due to band-to-band tunneling effects

TL;DR

This paper demonstrates high room-temperature magnetoresistance in p-i-n graphene nanoribbon heterostructures, leveraging band-to-band tunneling effects to significantly improve magnetic sensing performance.

Contribution

It introduces a novel p-i-n GNR heterostructure design that achieves high magnetoresistance at room temperature by suppressing thermal currents through band gaps.

Findings

High magnetoresistance ratio achieved at room temperature.

Edge-roughness and channel length increase magnetoresistance.

Channel width affects operating bias and device performance.

Abstract

A large magnetoresistance effect is obtained at room-temperature by using p-i-n armchair-graphene-nanoribbon (GNR) heterostructures. The key advantage is the virtual elimination of thermal currents due to the presence of band gaps in the contacts. The current at B=0T is greatly decreased while the current at B>0T is relatively large due to the band-to-band tunneling effects, resulting in a high magnetoresistance ratio, even at room-temperature. Moreover, we explore the effects of edge-roughness, length, and width of GNR channels on device performance. An increase in edge-roughness and channel length enhances the magnetoresistance ratio while increased channel width can reduce the operating bias.