Linear scaling between momentum and spin scattering in graphene

TL;DR

This study demonstrates a linear relationship between spin diffusion length and diffusion coefficient in graphene, suggesting that improving mobility could significantly enhance spin transport at room temperature.

Contribution

The paper provides experimental evidence of a linear scaling law between spin diffusion length and diffusion coefficient in graphene, linking spin relaxation to impurity scattering.

Findings

Linear scaling observed between spin diffusion length and diffusion coefficient

Electron-electron interactions are weak, transport limited by impurity scattering

Predicted increase in spin diffusion length with higher carrier mobility

Abstract

Spin transport in graphene carries the potential of a long spin diffusion length at room temperature. However, extrinsic relaxation processes limit the current experimental values to 1-2 um. We present Hanle spin precession measurements in gated lateral spin valve devices in the low to high (up to 10^13 cm^-2) carrier density range of graphene. A linear scaling between the spin diffusion length and the diffusion coefficient is observed. We measure nearly identical spin- and charge diffusion coefficients indicating that electron-electron interactions are relatively weak and transport is limited by impurity potential scattering. When extrapolated to the maximum carrier mobilities of 2x10^5 cm^2/Vs, our results predict that a considerable increase in the spin diffusion length should be possible.