Journal Article

FZJ-2020-02486

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Simulations on the Influence of Spatially Varying Spin Transport Parameters on the Measured Spin Lifetime in Graphene Non-Local Spin Valves

Drögeler, M.RWTH* ; Volmer, F.RWTH* ; Stampfer, C.FZJ* ; Beschoten, B. (Corresponding author)FZJ*RWTH*

2017
Wiley-VCH Weinheim

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Please use a persistent id in citations: http://hdl.handle.net/2128/25240  doi:10.1002/pssb.201700293

Abstract: Spin transport properties of graphene non‐local spin valve devices are typically determined from Hanle spin precession measurements by using a simplified solution of the one‐dimensional Bloch‐Torrey equation which assumes infinitely long transport channels and uniform spin transport parameter. We investigate the effects of a finite graphene size and explore the influence of spatially‐varying transport parameters on the measured Hanle curves by finite element simulations. We assume enhanced spin dephasing in the contact‐covered graphene areas with additional Fermi level pinning and explore the influence of non‐magnetic reference electrodes which are not properly decoupled from graphene. In experiments, it is typically observed that the spin lifetime increases with increasing charge carrier density. None of our simulations can reproduce this trend indicating that this dependency originates from spin transport through graphene areas which are not covered by contacts. We find that the extracted spin lifetime might be overestimated in flakes which are shorter than the spin diffusion length. Moreover, contact‐induced spin dephasing leads to an overall reduction of the extracted spin lifetime. Additionally, we show that non‐magnetic reference electrodes may also influence the measured spin lifetime even though they are not part of the transport area under investigation.

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Contributing Institute(s):

1. Halbleiter-Nanoelektronik (PGI-9)
2. JARA-FIT (JARA-FIT)

Research Program(s):

1. 522 - Controlling Spin-Based Phenomena (POF3-522) (POF3-522)

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Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DEAL Wiley ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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