All Electrical Access to Topological Transport Features in Mn1.8PtSn Films.
All Electrical Access to Topological Transport Features in Mn1.8PtSn Films.
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DOI：
10.1021/acs.nanolett.8b05042
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发表时间：
2018-12
期刊：
影响因子：
10.8
通讯作者：
R. Schlitz;P. Swekis;A. Markou;H. Reichlová;M. Lammel;J. Gayles;Andy Thomas;K. Nielsch;C. Felser;S. Goennenwein
中科院分区：
文献类型：
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作者：
R. Schlitz;P. Swekis;A. Markou;H. Reichlová;M. Lammel;J. Gayles;Andy Thomas;K. Nielsch;C. Felser;S. Goennenwein
非平凡磁拓扑的存在可以引起非零标量自旋手征，从而产生拓扑霍尔或能斯特效应。反过来，拓扑输运信号可以作为拓扑自旋结构的指标。这在薄膜或纳米图案化材料中特别重要，其中自旋结构不容易获得。传统上，通过将磁输运数据与独立的磁力测量实验相结合来确定拓扑响应。这种方法容易引入测量伪像。在本研究中，我们报告了在自旋重取向温度TSR低于190 K的情况下，在微图案化的Mn 1.8PtSn薄膜中观察到的大拓扑霍尔和能斯特效应。拓扑霍尔效应ρ xyT = 8 nΩm的幅度接近于在体Mn 2 PtSn中报道的值，并且在相同微结构中测量的拓扑能斯特效应S xyT = 115 nV K-1与体MnGe（S xyT = 150 nV K-1）报道的幅度相似，体MnGe是唯一报道拓扑能斯特的其他材料。我们使用我们的数据作为一个模型系统，引入一个拓扑量，这使得人们可以检测到拓扑输运效应的存在，而不需要独立的磁力测量数据。因此，我们的方法使拓扑输运的研究，也在纳米图案化的材料没有有害的磁化相关的限制。
The presence of nontrivial magnetic topology can give rise to nonvanishing scalar spin chirality and consequently a topological Hall or Nernst effect. In turn, topological transport signals can serve as indicators for topological spin structures. This is particularly important in thin films or nanopatterned materials where the spin structure is not readily accessible. Conventionally, the topological response is determined by combining magnetotransport data with an independent magnetometry experiment. This approach is prone to introduce measurement artifacts. In this study, we report the observation of large topological Hall and Nernst effects in micropatterned thin films of Mn1.8PtSn below the spin reorientation temperature TSR ≈ 190 K. The magnitude of the topological Hall effect ρ xyT = 8 nΩm is close to the value reported in bulk Mn2PtSn, and the topological Nernst effect S xyT = 115 nV K-1 measured in the same microstructure has a similar magnitude as reported for bulk MnGe ( S xyT ∼ 150 nV K-1), the only other material where a topological Nernst was reported. We use our data as a model system to introduce a topological quantity, which allows one to detect the presence of topological transport effects without the need for independent magnetometry data. Our approach thus enables the study of topological transport also in nanopatterned materials without detrimental magnetization related limitations.