Enhanced spin injection into single layer graphene with atomically smooth MgO barrier

Single layer graphene (SLG) is a promising material for spintronics due to predictions of long spin life time, and unusual spin dependent behaviors such as half-metallic ferromagnetism for graphene nanoribbons. Previously, we fabricated SLG spin valves utilizing transparent contacts Co/SLG with MgO masking layer, and observed gate tunable spin transport at room temperature (RT) [1]. For the non-local MR measurement (Figure 1a), spin is injected at electrode E2 and detected at E3. Figure 1b shows the non-local MR loop for a SLG spin valve with transparent contacts as the magnetic field is swept up (black curve) and swept down (red curve).