Edge magnetism in zigzag graphene nanoribbons with Rashba spin–orbit coupling

Abstract

We study the edge magnetism in zigzag graphene nanoribbons (ZGNRs) described by the mean-field Hubbard model with the controllable Rashba spin–orbit coupling (RSOC) at finite temperatures. The results show that the edge magnetic moments are robust against thermal fluctuation. Moreover, the magnitude of such edge magnetism can be significantly enhanced by the on-site Coulomb repulsion U, whereas RSOC yields the opposite effect. However, RSOC plays a crucial role in tuning the edge magnetism, which can drive the phase transition from the antiferromagnetic state into the ferromagnetic state in ZGNRs. When the ribbon width increases, the magnitudes of the edge magnetic moments under the weak U are apt to increase until reaching saturation. If U is large enough, the edge magnetism is almost independent of ribbon width. These versatile magnetic properties of ZGNRs could be useful in promising spintronics applications.