Spin Communication Over 30 Mu M Long Channels Of Chemical Vapor Deposited Graphene On Sio2

We demonstrate a high-yield fabrication of non-local spin valve devices with room-temperature spin lifetimes of up to 3 ns and spin relaxation lengths as long as 9 mu m in platinum-based chemical vapor deposition (Pt-CVD) synthesized single-layer graphene on SiO2/Si substrates. The spin-lifetime systematically presents a marked minimum at the charge neutrality point, as typically observed in pristine exfoliated graphene. However, by studying the carrier density dependence beyond n similar to 5 x 10(12) cm(-2), via electrostatic gating, it is found that the spin lifetime reaches a maximum and then starts decreasing, a behavior that is reminiscent of that predicted when the spin-relaxation is driven by spin-orbit interaction. The spin lifetimes and relaxation lengths compare well with stateof-the-art results using exfoliated graphene on SiO2/Si, being a factor two-to-three larger than the best values reported at room temperature using the same substrate. As a result, the spin signal can be readily measured across 30 mu m long graphene channels. These observations indicate that Pt-CVD graphene is a promising material for large-scale spin-based logic-in-memory applications.