Gate-tunable spin-dependent properties could be induced in graphene at room temperature through the magnetic proximity effect by placing it in contact with a metallic ferromagnet. Because strong chemical bonding with the metallic substrate makes gating ineffective, an intervening passivation layer is needed. Previously considered passivation layers result in a large shift of the Dirac point away from the Fermi level, so that unrealistically large gate fields are required to tune the spin polarization in graphene (Gr). We show that a monolayer of Au or Pt used as the passivation layer between Co and graphene brings the Dirac point closer to the Fermi level. In the $\text{Co}/\text{Pt}/\text{Gr}$ system the proximity-induced spin polarization in graphene and its gate control are strongly enhanced by the presence of a surface band near the Fermi level. Furthermore, the shift of the Dirac point could be eliminated entirely by selecting submonolayer coverage in the passivation layer. Our findings open a path towards experimental realization of an optimized two-dimensional system with gate-tunable spin-dependent properties.

中文翻译：

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石墨烯中的感应磁化：实现有效的自旋门控

通过使磁性石墨烯与金属铁磁体接触，可以在室温下通过磁性邻近效应在石墨烯中感应出栅极可调谐的自旋依赖性。由于与金属基材的牢固化学键合使门控无效，因此需要一个中间钝化层。先前考虑的钝化层会导致狄拉克点偏离费米能级较大，因此需要不切实际的大栅极场来调节石墨烯（Gr）的自旋极化。我们表明，用作Co和石墨烯之间钝化层的Au或Pt单层使Dirac点更接近费米能级。在里面$\text{有限公司}/\text{铂}/\text{GR}$通过在费米能级附近存在一个表面带，石墨烯中的邻近感应自旋极化及其栅极控制得到了显着增强。此外，通过选择钝化层中的亚单层覆盖率，可以完全消除狄拉克点的偏移。我们的发现为实验实现具有门可调自旋相关特性的优化二维系统开辟了道路。