State Key Laboratory for Mesoscopic Physics, School of Physics , Peking University , Beijing 100871 , China.
Institute for Quantum Science and Engineering and Department of Physics , South University of Science and Technology of China , Shenzhen 518055 , China.
Nano Lett. 2018 Apr 11;18(4):2435-2441. doi: 10.1021/acs.nanolett.7b05480. Epub 2018 Mar 15.
Graphene, having all atoms on its surface, is favorable to extend the functions by introducing the spin-orbit coupling and magnetism through proximity effect. Here, we report the tunable interfacial exchange field produced by proximity coupling in graphene/BiFeO heterostructures. The exchange field has a notable dependence with external magnetic field, and it is much larger under negative magnetic field than that under positive magnetic field. For negative external magnetic field, interfacial exchange coupling gives rise to evident spin splitting for N ≠ 0 Landau levels and a quantum Hall metal state for N = 0 Landau level. Our findings suggest graphene/BiFeO heterostructures are promising for spintronics.
石墨烯的所有原子都在其表面，通过近邻效应引入自旋轨道耦合和磁性，有利于扩展其功能。在这里，我们报告了在石墨烯/ BiFeO 异质结构中通过近邻耦合产生的可调谐界面交换场。该交换场对外磁场具有显著的依赖性，在外磁场为负时比为正时大得多。对于负的外磁场，界面交换耦合导致 N ≠ 0 朗道能级的明显自旋劈裂和 N = 0 朗道能级的量子霍尔金属态。我们的研究结果表明，石墨烯/ BiFeO 异质结构在自旋电子学方面具有广阔的应用前景。
