New developments in two-dimensional spintronics using large-scale graphene

Graphene is the two-dimensional (2D) platform for spin current communication and an integration medium for advanced 2D spintronic components. In devices where spin currents are generated by electrical spin injection into graphene, the contacts can lead to significant charge transfer doping of graphene, modifying its electrical properties locally and overall device performance. Also, substrate roughness puts a limit on the spin transport capability of large-scale graphene. This presentation will discuss our results on how device engineering using chemical vapor deposited graphene [1] can minimize contact-induced spin relaxation, enabling the realization of the longest spin communication of 45 µm and very high spin parameters in graphene at room temperature [2]. Furthermore, realizing highly resilient flexible ferromagnetic nanowires [3] allows us to fabricate flexible graphene spin devices and observe high diffusive spin transport in graphene [4], despite the rough topography of flexible substrates. At the same time, knowing the ability to maintain the integrity of metal-oxide graphene interfaces can increase their spintronic efficiencies in such devices [5]. These developments enhance our understanding of spin relaxation originating from contacts and substrates while opening up new grounds for flexible-integrated large-scale 2D spin current circuits and novel spin components.