Moriyama Takahiro, Kamiya Michinari, Oda Kent, Tanaka Kensho, Kim Kab-Jin, Ono Teruo
Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
Phys Rev Lett. 2017 Dec 29;119(26):267204. doi: 10.1103/PhysRevLett.119.267204.
Spin interaction in antiferromagnetic materials is of central interest in the recently emerging antiferromagnetic spintronics. In this Letter, we explore the spin current interaction in antiferromagnetic FeMn by the spin pumping effect. Exchange biased FeNi/FeMn films, in which the Néel vector can be presumably controlled via the exchange spring effect, are employed to investigate the damping enhancement depending on the relative orientation between the Néel vector and the polarization of the pumped spin current. The correlation between the enhanced damping and the strength of the exchange bias suggests that the twisting of the Néel vector induces an additional spin dissipation, which verifies that the Slonczewski-type spin torque is effective even in antiferromagnetic materials.
反铁磁材料中的自旋相互作用是最近兴起的反铁磁自旋电子学的核心研究内容。在本信函中，我们通过自旋泵浦效应来探究反铁磁FeMn中的自旋电流相互作用。利用交换偏置的FeNi/FeMn薄膜（其中奈尔矢量大概可通过交换弹簧效应来控制）来研究取决于奈尔矢量与泵浦自旋电流极化之间相对取向的阻尼增强情况。增强阻尼与交换偏置强度之间的相关性表明，奈尔矢量的扭转会引发额外的自旋耗散，这证实了即使在反铁磁材料中，斯隆切夫斯基型自旋扭矩也是有效的。
