Observation of excess polar magneto-optical Kerr effect signals in asymmetric Co/Tb-multilayers

IF 3.6 2区物理与天体物理 Q2 PHYSICS, APPLIED

Applied Physics Letters Pub Date : 2025-10-06 DOI:10.1063/5.0296892

Carmen Martín Valderrama, Mikel Quintana, Kazuhiko Tokunaga, Yoav Urbina, Yuichiro Kurokawa, Paolo Vavassori, Hiromi Yuasa, Andreas Berger

引用次数: 0

Abstract

We study the magneto-optical properties of asymmetric Co/Tb-multilayers that are designed to exhibit considerable Dzyaloshinskii–Moriya interaction (DMI) and low levels of effective perpendicular magnetic anisotropy. Accordingly, non-uniform magnetization states can occur in these films at intermediate magnetic field strengths, which cause a corresponding net magnetization reduction. Simultaneously, we observe an excess polar magneto-optical Kerr effect (MOKE) signal that increases beyond its value at saturation and is fully anticorrelated with the magnetization in its field dependency. We also find a very strong wavelength dependence of this excess polar MOKE signal that is very different from the MOKE behavior at saturation. All experimental data can be quantitatively explained by an additional polar MOKE mechanism that is associated with magnetic non-uniformities, such as, for instance, skyrmions, which have already been demonstrated to generate topological MOKE in certain compounds.

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非对称Co/ tb多层中过量极性磁光克尔效应信号的观测

我们研究了不对称Co/ tb多层材料的磁光特性，这些多层材料被设计成具有相当大的Dzyaloshinskii-Moriya相互作用（DMI）和低水平的有效垂直磁各向异性。因此，在中等磁场强度下，这些薄膜会出现非均匀磁化状态，从而导致相应的净磁化强度降低。同时，我们观察到一个超极磁光克尔效应（MOKE）信号，该信号在饱和时超过其值，并且在其场依赖性中与磁化强度完全反相关。我们还发现这种多余的极性MOKE信号的波长依赖性非常强，这与饱和时的MOKE行为非常不同。所有实验数据都可以通过与磁不均匀性相关的额外极性MOKE机制来定量解释，例如，skyrmions已经被证明可以在某些化合物中产生拓扑MOKE。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Applied Physics Letters 物理-物理：应用

CiteScore

6.40

自引率

10.00%

发文量

1821

审稿时长

1.6 months

期刊介绍： Applied Physics Letters (APL) features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, APL offers prompt publication of new experimental and theoretical papers reporting applications of physics phenomena to all branches of science, engineering, and modern technology. In addition to regular articles, the journal also publishes invited Fast Track, Perspectives, and in-depth Editorials which report on cutting-edge areas in applied physics. APL Perspectives are forward-looking invited letters which highlight recent developments or discoveries. Emphasis is placed on very recent developments, potentially disruptive technologies, open questions and possible solutions. They also include a mini-roadmap detailing where the community should direct efforts in order for the phenomena to be viable for application and the challenges associated with meeting that performance threshold. Perspectives are characterized by personal viewpoints and opinions of recognized experts in the field. Fast Track articles are invited original research articles that report results that are particularly novel and important or provide a significant advancement in an emerging field. Because of the urgency and scientific importance of the work, the peer review process is accelerated. If, during the review process, it becomes apparent that the paper does not meet the Fast Track criterion, it is returned to a normal track.