Spin orbit coupling effect on coherent transport properties of graphene nanoscopic rings in external magnetic field

A theoretical investigation of spin-orbit coupling effect on magnetotransport of a monolayer graphene system having the geometry of Aharonov-Bohm interferometer is presented. The spin-orbit interaction is considered in the form of Rashba spin-orbit (RSO) coupling. The problem is studied within atomistic tight-binding approximation in combination with non-equilibrium Green's functions formalism. The influence of RSO coupling on quantum interference effects is investigated within linear response limit in terms of transmission function and magnetoconductance as functions of Fermi energy, RSO coupling, magnetic flux and the number of transmission-modes as well as beyond this limit in terms of current-flow, under finite bias conditions. The Fourier power spectra of corresponding response functions are also obtained. The possibility of an effective control the two-terminal spin resolved resistances of the system and the spin polarization of equilibrium charge current as well as a nonequilibrium net current by means of RSO coupling and magnetic flux through the system, leading to an increase of the functionality of graphene in potential electronic applications, has been demonstrated.