Spin-generation in magnetic Weyl semimetal Co2MnGa across varying degree of chemical order
Spin-generation in magnetic Weyl semimetal Co2MnGa across varying degree of chemical order
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DOI：
10.1063/5.0102039
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发表时间：
2022-08
影响因子：
4
通讯作者：
Taqiyyah S. Safi;C. Chou;J. Hou;Jiahao Han;Luqiao Liu
中科院分区：
文献类型：
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作者：
Taqiyyah S. Safi;C. Chou;J. Hou;Jiahao Han;Luqiao Liu
最近发现的磁性Weyl半金属（MWSM），具有增强的Berry曲率源于其电子能带结构的拓扑结构，在自旋电子学应用中引起了广泛的兴趣。在这一类中，Co2MnGa，一种室温铁磁Heusler合金，作为拓扑驱动自旋电子应用的有前途的材料，已经引起了特别的兴趣。然而，到目前为止，通过自旋霍尔效应的自旋电流产生效率的结构顺序依赖性还没有在这种材料中得到充分的探索。本文研究了Co_2MnGa薄膜从化学无序的B_2相到有序的L_21相的磁性和输运性质的演变。我们还报告了自旋产生效率在这些不同阶段的变化，使用异质结构的Co2MnGa和亚铁磁体Co xTb1− x与垂直磁各向异性。我们在B2和L21相中测量了大的自旋霍尔角，并且在我们的实验极限内，我们没有观察到MWSM有序化在无序相上产生强自旋霍尔角所带来的优势，这表明在这些材料堆叠中内在的、外尔带结构确定的自旋霍尔效应上存在更复杂的机制。
Recently discovered magnetic Weyl semimetals (MWSM), with enhanced Berry curvature stemming from the topology of their electronic band structure, have gained much interest for spintronics applications. In this category, Co2MnGa, a room temperature ferromagnetic Heusler alloy, has garnered special interest as a promising material for topologically driven spintronic applications. However, until now, the structural-order dependence of spin current generation efficiency through the spin Hall effect has not been fully explored in this material. In this paper, we study the evolution of magnetic and transport properties of Co2MnGa thin films from the chemically disordered B2 to ordered L21 phase. We also report on the change in spin generation efficiency across these different phases, using heterostructures of Co2MnGa and ferrimagnet Co xTb1− x with perpendicular magnetic anisotropy. We measured large spin Hall angles in both the B2 and L21 phases, and within our experimental limits, we did not observe the advantage brought by the MWSM ordering in generating a strong spin Hall angle over the disordered phases, which suggests more complicated mechanisms over the intrinsic, Weyl-band structure-determined spin Hall effect in these material stacks.