Proximity-induced magnetization in graphene: Towards efficient spin gating
Proximity-induced magnetization in graphene: Towards efficient spin gating
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DOI：
10.1103/physrevmaterials.4.114006
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发表时间：
2020-11
影响因子：
3.4
通讯作者：
M. Bosnar;Ivor Lončarić;P. Lazic;K. Belashchenko;I. Žutić
中科院分区：
文献类型：
--
作者：
M. Bosnar;Ivor Lončarić;P. Lazic;K. Belashchenko;I. Žutić
通过将石墨烯与金属铁磁体接触，在室温下通过磁邻近效应可以在石墨烯中诱导栅极可调的自旋相关特性。由于与金属基材的强化学键合会使浇注无效，因此需要插入钝化层。之前考虑的钝化层会导致狄拉克点远离费米能级的较大偏移，因此需要不切实际的大栅极场来调节石墨烯（Gr）中的自旋极化。我们表明，单层 Au 或 Pt 用作 Co 和石墨烯之间的钝化层，使狄拉克点更接近费米能级。在 $\text{Co}/\text{Pt}/\text{Gr}$ 系统中，费米能级附近表面能带的存在强烈增强了石墨烯中邻近诱导的自旋极化及其栅极控制。此外，通过选择钝化层中的亚单层覆盖可以完全消除狄拉克点的偏移。我们的研究结果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一条道路。
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.