We demonstrate dynamic spin injection into chemical vapor deposition (CVD) grown graphene by spin pumping from permalloy (Py) layers. Ferromagnetic resonance measurements at room temperature reveal a strong enhancement of the Gilbert damping at the Py/graphene interface, exceeding that observed in even Py/platinum interfaces. Similar results are also shown on Co/graphene layers. This enhancement in the Gilbert damping is understood as the consequence of spin pumping at the interface driven by magnetization dynamics. Our observations suggest a strong enhancement of spin-orbit coupling in CVD graphene, in agreement with earlier spin valve measurements.
@article{arxiv.1211.0492,
title = {Dynamic Spin Injection into Chemical Vapor Deposited Graphene},
author = {A. K. Patra and S. Singh and B. Barin and Y. Lee and J. -H. Ahn and E. del Barco and E. R. Mucciolo and B. Özyilmaz},
journal= {arXiv preprint arXiv:1211.0492},
year = {2012}
}