Spin pumping into two-dimensional electron systems
  We study the spin current injected by spin pumping into single layer graphene and the two-dimensional electron gas (2DEG) with ferromagnetic contacts using scattering theory. The spin currents pumped into graphene are very distinct from that into the 2DEG since importantly affected by Klein tunneling. 
Takuya Inoue, Gerrit E. W. Bauer, Kentaro Nomura
cond-mat.mes-hall