1D ferromagnetic edge contacts to 2D graphene/h-BN heterostructures
Karpiak, Bogdan (Chalmers University of Technology (Göteborg, Suècia))
Dankert, André (Chalmers University of Technology (Göteborg, Suècia))
Cummings, Aron (Institut Català de Nanociència i Nanotecnologia)
Power, Stephen R. (Institut Català de Nanociència i Nanotecnologia)
Roche, Stephan (Institut Català de Nanociència i Nanotecnologia)
Dash, Saroj P. (Chalmers University of Technology (Göteborg, Suècia))

Date:	2018
Abstract:	We report the fabrication of one-dimensional (1D) ferromagnetic edge contacts to two-dimensional (2D) graphene/h-BN heterostructures. While aiming to study spin injection/detection with 1D edge contacts, a spurious magnetoresistance signal was observed, which is found to originate from the local Hall effect in graphene due to fringe fields from ferromagnetic edge contacts and in the presence of charge current spreading in the nonlocal measurement configuration. Such behavior has been confirmed by the absence of a Hanle signal and gate-dependent magnetoresistance measurements that reveal a change in sign of the signal for the electron- and hole-doped regimes, which is in contrast to the expected behavior of the spin signal. Calculations show that the contact-induced fringe fields are typically on the order of hundreds of mT, but can be reduced below 100 mT with careful optimization of the contact geometry. There may be an additional contribution from magnetoresistance effects due to tunneling anisotropy in the contacts, which needs further investigation. These studies are useful for optimization of spin injection and detection in 2D material heterostructures through 1D edge contacts.
Grants:	Ministerio de Economía y Competitividad SEV-2013-0295 European Commission 665919 European Commission 604391 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-58 Ministerio de Economía y Competitividad FIS2015-67767-P Ministerio de Economía y Competitividad MAT2012-33911
Note:	Altres ajuts: EU FlagEra project (No. 2015-06813)
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	1D edge contact ; CVD ; Graphene ; H-bn ; Spin-valve ; Spintronics ; Stray field
Published in:	2D Materials, Vol. 5, Núm. 1 (January 2018) , article 14001, ISSN 2053-1583

DOI: 10.1088/2053-1583/aa8d2b

Post-print 15 p, 1.0 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles