Graphene-WS${}_2$ heterostructures for tunable spin injection and spin transport

Abstract

We report the first measurements of spin injection in to graphene through a 20 nm thick tungsten disulphide (WS${}_2$) layer, along with a modified spin relaxation time (τs) in graphene in the WS${}_2$ environment, via spin-valve and Hanle spin-precession measurements, respectively. First, during the spin-injection into graphene through a WS${}_2$-graphene interface, we can tune the interface resistance at different current bias and modify the spin injection efficiency, in a correlation with the conductivity-mismatch theory. Temperature assisted tunneling is identified as a dominant mechanism for the charge transport across the interface. Second, we measure the spin transport in graphene, underneath the WS${}_2$ crystal and observe a significant reduction in the τs down to 17 ps in graphene in the WS${}_2$ covered region, compared to that in its pristine state. The reduced τs indicates the WS${}_2$-proximity induced additional dephasing of the spins in graphene.

7 Pages, 6 figures

References in corpus (9)

• Vertical Field Effect Transistor based on Graphene-WS2 Heterostructures for flexible and transparent electronics
• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• Spin-Orbit Proximity Effect in Graphene
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Cited by in corpus (3)

• Large Proximity-Induced Spin Lifetime Anisotropy in Transition Metal Dichalcogenide/Graphene Heterostructures
• Proximity effects in bilayer graphene on monolayer WSe${}_2$: Field-effect spin-valley locking, spin-orbit valve, and spin transistor
• Spin transport in high-mobility graphene on WS${}_2$ substrate with electric-field tunable proximity spin-orbit interaction