Topological antiferromagnetic spin valve

拓扑反铁磁自旋阀

• 批准号: 21F21045
• 负责人: 中辻 知
• 金额: $ 1.54万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2021
• 资助国家: 日本
• 起止时间: 2021-04-28 至 2023-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-21F21045/
• 关键词: antiferromagnets; TMR; nonvolatile memory

In FM/NM/FM trilayers (FM: ferromagnet, NM: nonmagnet), the change of relative orientation between the two FM moments could lead to varying opposition to the tunneling current flow: this tunneling magnetoresistance (TMR) is proportional to the spin polarization of FMs as is characterized by the Julliere’s model, and thus it is not usually seen in antiferromagnets with negligible spin polarization. Here, we demonstrate the existence of antiferromagnetic TMR in a magnetic octupole valve Mn3Sn/MgO/Mn3Sn, supported by the theory. Remarkably, although the spin polarization rate is three orders smaller than that of Fe, Mn3Sn/MgO/Mn3Sn shows 5 times larger TMR than Fe/MgO/Mn3S. This emphasizes the dominant role of octupole polarization, instead of spin polarization.

在 FM/NM/FM 三层（FM：铁磁体，NM：非磁体）中，两个 FM 力矩之间相对方向的变化可能会导致对隧道电流流动的不同反对：这种隧道磁阻 (TMR) 与自旋极化成正比FM 的特征是由 Julliere 模型表征的，因此在自旋极化可忽略不计的反铁磁体中通常不会看到 FM 的存在。磁性八极管 Mn3Sn/MgO/Mn3Sn 中的反铁磁 TMR，得到理论支持 值得注意的是，尽管自旋极化率比 Fe 小三个数量级，但 Mn3Sn/MgO/Mn3Sn 的 TMR 比 Fe/MgO/Mn3S 大 5 倍。这强调了八极极化而不是自旋极化的主导作用。