Controlling the spin conductance in a graphene zigzag hexagonal quantum ring connected to three leads in the presence of spin-orbit interaction and magnetic field

In this work, we theoretically investigate the spin dependent conductance and polarization in a Hexagonal graphene ring (HGR) with zigzag edges connected to three semi-infinite leads in the presence of a perpendicular magnetic flux and Rashba spin-orbit interaction (RSOI). Results are obtained using the tight-binding model within the non-equilibrium Green’s function formalism and suggest that in the absence of magnetic flux, for appropriate values of Rashba strength and energy of the incoming electrons; high spin-polarized conductances with opposite direction can be obtained for right up and right down leads, respectively. In this case, the system can act as a spin spliting device. In addition, it is found that by applying a magnetic flux to the central region of the HGR, it is possible to determine the magnitude and direction of polarization in output leads due to the time reversal breaking so, the system can be consider as a good candidate for the spintronic applications.