Large positive in-plane magnetoresistance induced by localized states at nanodomain boundaries in graphene

Han Wu ,Olaf Lübben,Huajun Liu,M I Katsnelson ,Byong Sun Chun,А Н Чайка ,V Yu Aristov ,Mohamed Abid,С Н Молотков ,Tsung‐Wei Huang ,I V Shvets ,Muhammad Abid ,Sergey A Krasnikov,Yahya T Janabi,S Babenkov ,A I Lichtenstein ,Ming Chien Hsu ,Yuran Niu,Barry E Murphy,О В Молодцова ,Ching-Hung Chang

doi:10.1038/ncomms14453

Abstract

Graphene supports long spin lifetimes and long diffusion lengths at room temperature, making it highly promising for spintronics. However, making graphene magnetic remains a principal challenge despite the many proposed solutions. Among these, graphene with zig-zag edges and ripples are the most promising candidates, as zig-zag edges are predicted to host spin-polarized electronic states, and spin–orbit coupling can be induced by ripples. Here we investigate the magnetoresistance of graphene grown on technologically relevant SiC/Si(001) wafers, where inherent nanodomain boundaries sandwich zig-zag structures between adjacent ripples of large curvature. Localized states at the nanodomain boundaries result in an unprecedented positive in-plane magnetoresistance with a strong temperature dependence. Our work may offer a tantalizing way to add the spin degree of freedom to graphene.

Highlights

Graphene supports long spin lifetimes and long diffusion lengths at room temperature, making it highly promising for spintronics
High-resolution scanning tunnelling microscopy (STM) images of the nanodomain boundaries (NBs) between the 27°-rotated lattices show that, in most cases, the NBs are rotated by 3.5° relative to the one of the two orthogonal o1104 directions leading to an asymmetrical rotation of the graphene lattices in the neighbouring domains
They are rotated by 17° clockwise and 10° counterclockwise relative to the NBs, and there is a zig-zag structure on one side and an armchair structure on the other side of the NBs (Fig. 1c)[36]

Summary

Introduction

Graphene supports long spin lifetimes and long diffusion lengths at room temperature, making it highly promising for spintronics. Graphene is known for its extraordinary electronic properties, such as high electron mobility and tunable charge carrier concentration[2,3] It has the capacity for room-temperature spin transport, with propagation diffusion lengths of several micrometres, making it a highly promising material for spintronics[4,5,6,7,8,9,10]. 100 K, the Zeeman effect leads to the inequivalent confinement of electrons with different spins from the two-dimensional (2D) sheet to the 1D NBs, which produces the positive MR observed at higher temperatures This behaviour shows that it is possible to engineer new tunable electronic and magnetic nanostructures purely from graphene

Methods

Results

Conclusion