Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, 160 00, Prague 6, Czech Republic.
Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 12116, Prague 2, Czech Republic.
Nat Commun. 2018 Nov 8;9(1):4686. doi: 10.1038/s41467-018-07092-2.
Antiferromagnets are enriching spintronics research by many favorable properties that include insensitivity to magnetic fields, neuromorphic memory characteristics, and ultra-fast spin dynamics. Designing memory devices with electrical writing and reading is one of the central topics of antiferromagnetic spintronics. So far, such a combined functionality has been demonstrated via 90° reorientations of the Néel vector generated by the current-induced spin orbit torque and sensed by the linear-response anisotropic magnetoresistance. Here we show that in the same antiferromagnetic CuMnAs films as used in these earlier experiments we can also control 180° Néel vector reversals by switching the polarity of the writing current. Moreover, the two stable states with opposite Néel vector orientations in this collinear antiferromagnet can be electrically distinguished by measuring a second-order magnetoresistance effect. We discuss the general magnetic point group symmetries allowing for this electrical readout effect and its specific microscopic origin in CuMnAs.
反铁磁体通过许多有利的特性丰富了自旋电子学研究，包括对磁场的不敏感性、类神经形态记忆特性和超快自旋动力学。设计具有电写入和读取功能的存储器件是反铁磁自旋电子学的核心课题之一。到目前为止，这种组合功能已经通过电流诱导的自旋轨道扭矩产生的奈耳矢量的 90°重定向和通过线性响应各向异性磁电阻感应来证明。在这里，我们表明，在与之前实验中使用的相同的 CuMnAs 反铁磁薄膜中，我们也可以通过切换写入电流的极性来控制 180°奈耳矢量反转。此外，在这个共线反铁磁体中，具有相反奈耳矢量方向的两个稳定状态可以通过测量二阶磁电阻效应来电区分。我们讨论了允许这种电读出效应的一般磁点群对称性及其在 CuMnAs 中的具体微观起源。
