  We investigate theoretically the spin-independent tunneling magnetoresistance
effect in a graphene monolayer modulated by two parallel ferromagnets deposited
on a dielectric layer. For the parallel magnetization configuration, Klein
tunneling can be observed in the transmission spectrum, but at specific oblique
incident angles. For the antiparallel magnetization configuration, the
transmission can be blocked by the magnetic-electric barrier provided by the
ferromagnets. Such a transmission discrepancy results in a tremendous
magnetoresistance ratio and can be tuned by the inclusion of an electric
barrier.
