Synthesis of crystallographically well-defined thin films of topological materials is important for unraveling their mesoscale quantum properties and for device applications. ${\mathrm{Mn}}_3\mathrm{Ge}$, an antiferromagnetic Weyl semimetal with a chiral magnetic structure on a kagome lattice, is expected to have enhanced Berry curvature around Weyl nodes near the Fermi energy, leading to large anomalous Hall/Nernst effects and a large spin-Hall effect. Using magnetron sputtering, we have grown epitaxial thin films of hexagonal $\mathrm{D}{0}_{19}{\mathrm{Mn}}_3\mathrm{Ge}$ that are flat and continuous. Large anomalous Nernst and inverse spin-Hall effects are observed in thermoelectric and spin-pumping devices. The anomalous Nernst signal in our ${\mathrm{Mn}}_3\mathrm{Ge}$ films is estimated to be 0.1 μV/K and is comparable to that in ferromagnetic Fe, despite ${\mathrm{Mn}}_3\mathrm{Ge}$ having a weak magnetization of $\sim 3.5\mathrm{m}{\mu }_{\mathrm{B}}/\mathrm{Mn}$ at room temperature. The spin-mixing conductance is $90.5{\mathrm{nm}}^{-2}$ at the $\mathrm{Py}/{\mathrm{Mn}}_3\mathrm{Ge}$ interface, and the spin-Hall angle in ${\mathrm{Mn}}_3\mathrm{Ge}$ is estimated to be about eight times of that in Pt.

中文翻译：

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kagome半金属Mn3Ge外延薄膜中的大反常能斯特和自旋霍尔效应

晶体学上定义明确的拓扑材料薄膜的合成对于揭示其中尺度量子特性和器件应用很重要。 ${锰}_3\mathrm{通用电器}$，一种在铁丝网上具有手性磁性结构的反铁磁Weyl半金属，有望在费米能量附近的Weyl节点周围增强Berry曲率，从而导致大的霍尔/能斯特反常效应和自旋霍尔效应。使用磁控溅射，我们已经生长了六角形的外延薄膜$\mathrm{d}{0}_{19}{锰}_3\mathrm{通用电器}$平坦连续的 在热电和自旋泵浦装置中观察到了大的反常能斯特效应和逆自旋霍尔效应。我们的Nernst异常信号${锰}_3\mathrm{通用电器}$ 尽管薄膜厚度估计为0.1μV/ K，并且与铁磁性Fe薄膜相当，尽管 ${锰}_3\mathrm{通用电器}$ 具有弱的磁化强度 $〜3.5\mathrm{米}{\mu }_{\mathrm{乙}}/锰$在室温下。自旋混合电导为$90.5{\mathrm{纳米}}^{-2}$ 在 $y/{锰}_3\mathrm{通用电器}$ 界面和自旋霍尔角 ${锰}_3\mathrm{通用电器}$ 据估计约为Pt的八倍。