Electron-Hole Asymmetry of Spin Injection and Transport in Single-Layer Graphene

TL;DR

This study investigates the spin injection and transport properties in single-layer graphene, revealing an electron-hole asymmetry in non-local magnetoresistance that depends on gate voltage and bias, with implications for spintronic applications.

Contribution

It uncovers an electron-hole asymmetry in spin transport in graphene, contrasting with the symmetric band structure, and demonstrates the dependence of non-local MR on bias for holes but not electrons.

Findings

Non-local MR proportional to conductivity for electrons and holes.

Electron-hole asymmetry in bias dependence of non-local MR.

Spin transport behavior differs between electron and hole doping.

Abstract

Spin-dependent properties of single-layer graphene (SLG) have been studied by non-local spin valve measurements at room temperature. Gate voltage dependence shows that the non-local magnetoresistance (MR) is proportional to the conductivity of the SLG, which is the predicted behavior for transparent ferromagnetic/nonmagnetic contacts. While the electron and hole bands in SLG are symmetric, gate voltage and bias dependence of the non-local MR reveal an electron-hole asymmetry in which the non-local MR is roughly independent of bias for electrons, but varies significantly with bias for holes.