Spin filtering by proximity effects at hybridized interfaces in spin-valves with 2D graphene barriers

Maëlis Piquemal-Banci (1) , Regina Galceran (1) , Simon M.-M. Dubois , Victor Zatko (1) , Marta Galbiati (1) , Florian Godel (1) , Marie-Blandine Martin (1) , Robert Weatherup , Frédéric Petroff (1) , Albert Fert (1) , Jean-Christophe Charlier , John Robertson , Stephan Hofmann , Bruno Dlubak (1) , Pierre Seneor (1)

1 Laboratoire Albert Fert (ex-UMPhy Unité mixte de physique CNRS/Thales)

We report on spin transport in state-of-the-art epitaxial monolayer graphene based 2D magnetic tunnel junctions (2D-MTJs). In our measurements, supported by ab-initio calculations, the strength of interaction between ferromagnetic electrodes and graphene monolayers is shown to fundamentally control the resulting spin signal. In particular, by switching the graphene/ferromagnet interaction, spin transport reveals magneto-resistance signal MR > 80% in junctions with low resistance × area products. Descriptions based only on a simple K-point filtering picture (i.e. MR increase with the number of layers) are not sufficient to predict the behavior of our devices. We emphasize that hybridization effects need to be taken into account to fully grasp the spin properties (such as spin dependent density of states) when 2D materials are used as ultimately thin interfaces. While this is only a first demonstration, we thus introduce the fruitful potential of spin manipulation by proximity effect at the hybridized 2D material / ferromagnet interface for 2D-MTJs.

Domaines: Physique [physics]; Matière Condensée [cond-mat]

Maëlis Piquemal-Banci, Regina Galceran, Simon M.-M. Dubois, Victor Zatko, Marta Galbiati, et al.. Spin filtering by proximity effects at hybridized interfaces in spin-valves with 2D graphene barriers. Nature Communications, 2020, 11 (5670), ⟨10.1038/s41467-020-19420-6⟩. ⟨hal-03033326⟩