Drift current induced tunable spin current in inverted-graphene based spin valve

Journal article, 2025

Understanding the interplay between electrical current and spin current in graphene is crucial for the realization of the potential of the graphene-based spintronic devices. In this work, we investigate spin transport under both bias (the DC current applied within an injection circuit) and external currents (applied beyond the injection circuit), emphasizing the pivotal role of the drift field, in the inverted graphene-based spin valve. We discover that the spin current can be effectively tuned with electrical current, exhibiting notable differences at various gate voltages. Further Hanle measurements confirm that external electrical current not only tunes the spin diffusion current but also simultaneously enhances the spin-injection polarization. We observe a strong nonlinear bias behavior, particularly with a reversal of the sign of the spin signal at negative bias currents, demonstrating the spin drift effect. These findings underscore the importance of drift current in affecting spin transport in the graphene-based spin devices.