Scaling of the Nonlocal Spin and Baseline Resistances in Graphene Lateral Spin Valves

Jiaxi Hu, Gordon Stecklein, David A. Deen, Qun Su, Paul A. Crowell, Steven J. Koester

Research output: Contribution to journalArticle

Abstract

Graphene lateral spin valves (LSVs) are promising devices for future memory and magnetic field sensing applications. In this article, we study the dependence of the nonlocal spin resistance,RNL, and the baseline resistance, RBS, as a function of the graphene channel width, W. The scaling trend is quantitatively assessed by using graphene deposited by chemical vapor deposition, which provides a large number of devices with consistent performance.AsWis scaled from 10 to 0.5μm, the change in RNL matches the theory of contact-induced spin relaxation with a current spin polarization of 3%-5% and a spin diffusion length of λs = 1.5-2.5 ìm. We also observe a systematic and dramatic decrease in RBS, which we attribute to the reduction in charge current spreading. However, we find in the narrowest devices that a small RBS remains that arises due to thermoelectric effects, and this trend is confirmed using gate voltage-A nd charge current-dependentanalyses. Finally, we introduce a nonideality factor, m = |RBS/RNL|, as a figure of merit to describe the suppression of the baseline relative to the spin signal. In an LSV with L = 1.5 μm, W = 0.5 μm, and n-type conduction, the nonideality factor is as low asm = 0.0252± 0.0202 at room temperature showing that nearly ideal bipolar and symmetric spin signals can be achieved in graphene LSVs.

Original languageEnglish (US)
Article number8871329
Pages (from-to)5003-5010
Number of pages8
JournalIEEE Transactions on Electron Devices
Volume66
Issue number11
DOIs
StatePublished - Nov 2019

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Graphene
Thermoelectricity
Spin polarization
Chemical vapor deposition
Magnetic fields
Data storage equipment
Electric potential
Temperature

Keywords

  • Ferromagnet
  • graphene
  • lateral spin valve (LSV)

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Reporting period for MRSEC

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Cite this

Scaling of the Nonlocal Spin and Baseline Resistances in Graphene Lateral Spin Valves. / Hu, Jiaxi; Stecklein, Gordon; Deen, David A.; Su, Qun; Crowell, Paul A.; Koester, Steven J.

In: IEEE Transactions on Electron Devices, Vol. 66, No. 11, 8871329, 11.2019, p. 5003-5010.

Research output: Contribution to journalArticle

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