We report the first measurements of spin injection in to graphene through a 20 nm thick tungsten disulphide (WS2) layer, along with a modified spin relaxation time ({\tau}s) in graphene in the WS2 environment, via spin-valve and Hanle spin-precession measurements, respectively. First, during the spin-injection into graphene through a WS2-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 WS2 crystal and observe a significant reduction in the {\tau}s down to 17 ps in graphene in the WS2 covered region, compared to that in its pristine state. The reduced {\tau}s indicates the WS2-proximity induced additional dephasing of the spins in graphene.
@article{arxiv.1610.07196,
title = {Graphene-WS$_2$ heterostructures for tunable spin injection and spin transport},
author = {Siddhartha Omar and Bart J. van Wees},
journal= {arXiv preprint arXiv:1610.07196},
year = {2017}
}