  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.
