Resistive contribution in electrical-switching experiments with antiferromagnets
Resistive contribution in electrical-switching experiments with antiferromagnets
复制标题
DOI：
10.1103/physrevresearch.2.033077
复制
发表时间：
2020-07-15
影响因子：
4.2
通讯作者：
Meinert, Markus
中科院分区：
文献类型：
--
作者：
Matalla-Wagner, Tristan;Schmalhorst, Jan-Michael;Meinert, Markus
最近的研究表明，反铁磁体的电开关通过内禀自旋轨道力矩或相邻重金属层的自旋霍尔效应。电读出通常通过测量分别具有四个或八个臂的平面十字形或星形装置处的横向各向异性磁阻来实现。根据材料的不同，切换磁状态所需的电流密度可能很大，通常接近器件的破坏阈值。我们证明，由此产生的电应力局部改变了薄膜的电阻率，从而打破了导体的四重旋转对称性。由于膜的不均匀性，这种对称性破坏产生类似于各向异性磁阻的信号，并且在实验上被视为“锯齿”形的横向电阻率。这种伪影可以在开关实验的多次重复中持续存在，并且不容易与磁贡献分离。我们讨论的工件的起源，阐明薄膜结晶度的作用，并提出了如何分离的电阻贡献的磁贡献的方法。
Recent research demonstrated the electrical switching of antiferromagnets via intrinsic spin-orbit torque or the spin Hall effect of an adjacent heavy metal layer. The electrical readout is typically realized by measuring the transverse anisotropic magnetoresistance at planar cross- or star-shaped devices with four or eight arms, respectively. Depending on the material, the current density necessary to switch the magnetic state can be large, often close to the destruction threshold of the device. We demonstrate that the resulting electrical stress changes the film resistivity locally and thereby breaks the fourfold rotational symmetry of the conductor. This symmetry breaking due to film inhomogeneity produces signals, that resemble the anisotropic magnetoresistance and is experimentally seen as a "saw-tooth"-shaped transverse resistivity. This artifact can persist over many repeats of the switching experiment and is not easily separable from the magnetic contribution. We discuss the origin of the artifact, elucidate the role of the film crystallinity, and propose approaches how to separate the resistive contribution from the magnetic contribution.