Tunable magnetoresistance in spin-orbit coupled graphene junctions

•We propose novel ways to generate and control the population of spins in graphene nanostructures that provide a way to extending the application of graphene-based junction in spintronics.•We show that the angle-resolved transmission probability can be tuned by the Rashba spin-orbit (RSO) strength.•The transmission spectrum shows Klein tunneling in the parallel (P) magnetization configuration which can be blocked by the RSO interaction.•The calculated spin-polarized conductance is a sensitive oscillatory function of the thickness of RSO region.•Because of the spin-flip effect, the junction shows a spin-valve feature with large and negative magnetoresistance (MR) and spin-magnetoresistance (SMR) in the presence of RSO coupling. Using the Landauer-Bütikker formalism, we study the graphene magneto-transport in the presence of Rashba spin-orbit interaction (RSOI). we show that the angle resolved transmission probability in the proposed structures can be tuned by the RSOI strength. The transmission spectrum show Klein tunneling in the parallel (P) magnetization configuration which can be blocked by the RSOI. This effect is also observable for the anti-parallel (AP) magnetization configuration in different incident angle. The numerical results shows that the spin-polarized conductance strongly depends on the strength of the RSOI and can be generated by tuning the magnetic exchange field and RSOI strength. This spin-polarized conductance is a sensitive oscillatory function of the thickness of the RSO region. Because of the spin-flip effect, the junction shows a spin-valve effect with large and negative magnetoresistance (MR) and spin-magnetoresistance (SMR) in the presence of RSOI. When the RSOI is on, the frequency and amplitude of shot-noise and Fano factor’s oscillations are also increased. These results can provide a way to extending the application of graphene-based junctions in spintronics.