Dirac Cone Spin Polarization of Graphene by Magnetic Insulator Proximity Effect Probed with Outermost Surface Spin Spectroscopy
Dirac Cone Spin Polarization of Graphene by Magnetic Insulator Proximity Effect Probed with Outermost Surface Spin Spectroscopy
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DOI：
10.1002/adfm.201800462
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发表时间：
2018-05
影响因子：
19
通讯作者：
S. Sakai;Sergei V. Erohin;Z. Popov;Satoshi Haku;Takahiro Watanabe;Y. Yamada;S. Entani;Songtian Li;P. Avramov;H. Naramoto;K. Ando;P. Sorokin;Y. Yamauchi
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文献类型：
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作者：
S. Sakai;Sergei V. Erohin;Z. Popov;Satoshi Haku;Takahiro Watanabe;Y. Yamada;S. Entani;Songtian Li;P. Avramov;H. Naramoto;K. Ando;P. Sorokin;Y. Yamauchi
利用自旋极化亚稳He原子束的最外表面自旋光谱研究了单层石墨烯（SLG）和钇铁石榴石Y3Fe5O12 （YIG）的异质结构，探讨了磁性绝缘体近距离接触对石墨烯自旋相关电子结构的影响。在SLG/YIG异质结构中，石墨烯的Dirac锥电子与YIG的少数自旋平行发生负自旋极化，极化度较大，但π带结构没有发生明显变化。理论计算表明，静电界面相互作用提供了强大的物理粘附，间接交换相互作用导致SLG在与YIG的界面处自旋极化。由于异常霍尔效应，SLG/YIG异质结构的霍尔器件表现出非线性霍尔电阻，这意味着自旋轨道相互作用是邻近效应的另一种表现。
The effects of the proximity contact with magnetic insulator on the spin‐dependent electronic structure of graphene are explored for the heterostructure of single‐layer graphene (SLG) and yttrium iron garnet Y3Fe5O12 (YIG) by means of outermost surface spin spectroscopy using a spin‐polarized metastable He atom beam. In the SLG/YIG heterostructure, the Dirac cone electrons of graphene are found to be negatively spin polarized in parallel to the minority spins of YIG with a large polarization degree, without giving rise to significant changes in the π band structure. Theoretical calculations reveal the electrostatic interfacial interactions providing a strong physical adhesion and the indirect exchange interaction causing the spin polarization of SLG at the interface with YIG. The Hall device of the SLG/YIG heterostructure exhibits a nonlinear Hall resistance attributable to the anomalous Hall effect, implying the extrinsic spin–orbit interactions as another manifestation of the proximity effect.