Spin Relaxation in Single Layer Graphene with Tunable Mobility
  Graphene is an attractive material for spintronics due to theoretical predictions of long spin lifetimes arising from low spin-orbit and hyperfine couplings. In experiments, however, spin lifetimes in single layer graphene (SLG) measured via Hanle effects are much shorter than expected theoretically. Thus, the origin of spin relaxation in SLG is a major issue for graphene spintronics. Despite extensive theoretical and experimental work addressing this question, there is still little clarity on the microscopic origin of spin relaxation. By using organic ligand-bound nanoparticles as charge reservoirs to tune mobility between 2700 and 12000 cm2/Vs, we successfully isolate the effect of charged impurity scattering on spin relaxation in SLG. Our results demonstrate that while charged impurities can greatly affect mobility, the spin lifetimes are not affected by charged impurity scattering. 
Wei Han, Jen-Ru Chen, Deqi Wang, Kathleen M. McCreary, Hua Wen, Adrian   G. Swartz, Jing Shi, Roland K. Kawakami
cond-mat.mes-hall cond-mat.mtrl-sci