Room temperature two terminal tunnel magnetoresistance in lateral graphene transistor

TL;DR

This study demonstrates room-temperature local tunnel magnetoresistance in a lateral graphene transistor, highlighting the device's potential for spintronic applications with efficient spin current control.

Contribution

First observation of room-temperature local tunnel magnetoresistance in a lateral graphene transistor using standard fabrication processes.

Findings

High spin diffusion length in pristine graphene

Room-temperature local tunnel magnetoresistance observed

Spin-polarized current switching enhanced by external gate voltage

Abstract

We investigate the behavior of both pure spin and spin-polarized currents measured with four probe non-local and two probe local configurations up to room temperature and under external gate voltage in a lateral graphene transistor, produced using a standard large-scale microfabrication process. The high spin diffusion length of pristine graphene in the channel, measured both directly and by the Hanle effect, and the tuning of relation between electrode resistance area present in the device architecture, allowed us to observe local tunnel magnetoresistance at room temperature, a new finding for this type of device. Results also indicate that while pure spin currents are less sensitive to temperature variations, spin-polarized current switching by external voltage is more efficient, due to a combination of the Rashba effect and change in carrier mobility by Fermi level shift