Experimental Observation of Exchange-Driven Chiral Effects in Curvilinear Magnetism.
Experimental Observation of Exchange-Driven Chiral Effects in Curvilinear Magnetism.
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DOI：
10.1103/physrevlett.123.077201
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发表时间：
2019-08
影响因子：
8.6
通讯作者：
O. Volkov;A. Kákay;F. Kronast;I. Mönch;M. Mawass;J. Fassbender;D. Makarov
中科院分区：
文献类型：
--
作者：
O. Volkov;A. Kákay;F. Kronast;I. Mönch;M. Mawass;J. Fassbender;D. Makarov
磁性材料中手征对称性破缺的主要原因是反对称交换相互作用，即本征Dzyaloshinskii-Moriya相互作用(DMI)。最近，许多振奋人心的理论工作预测，薄膜在曲面上的弯曲往往足以引起类似的手征效应。然而，它们源于交换或静磁相互作用，可以稳定非共线磁结构或影响自旋波的传播。在这里，我们证明了曲率诱导的手征效应是实验上可以观察到的，而不是理论抽象的，甚至在传统的软铁磁材料中也存在。结果表明，通过在最简单的抛物线上测量磁区壁脱钉场，可以量化有效的交换驱动的DMI相互作用常数。值得注意的是，它的值可以高达薄膜的界面DMI常数，并且可以通过抛物线的曲率来调节。
The main origin of the chiral symmetry breaking and, thus, for the magnetochiral effects in magnetic materials is associated with an antisymmetric exchange interaction, the intrinsic Dzyaloshinskii-Moriya interaction (DMI). Recently, numerous inspiring theoretical works predict that the bending of a thin film to a curved surface is often sufficient to induce similar chiral effects. However, these originate from the exchange or magnetostatic interactions and can stabilize noncollinear magnetic structures or influence spin-wave propagation. Here, we demonstrate that curvature-induced chiral effects are experimentally observable rather than theoretical abstraction and are present even in conventional soft ferromagnetic materials. We show that, by measuring the depinning field of domain walls in the simplest possible curve, a flat parabolic stripe, the effective exchange-driven DMI interaction constant can be quantified. Remarkably, its value can be as high as the interfacial DMI constant for thin films and can be tuned by the parabola's curvature.