标题： 室温铁磁半赫斯勒合金PtMnBi中的巨反常霍尔电导率和吉尔伯特阻尼 显示英文标题

标题： Giant Anomalous Hall Conductivity and Gilbert Damping in Room-temperature Ferromagnetic Half-Heusler Alloys PtMnBi

摘要： 半赫斯勒合金由于其优异的特性，包括高于室温的高居里温度（TC）和大的反常霍尔电导率（AHC），已成为新型自旋电子学应用的有希望的候选材料。在本工作中，我们使用第一性原理计算和蒙特卡罗模拟系统地研究了PtMnBi在{\alpha }-、\{beta\}-和{\gamma }-相中的磁性和电子性质。发现这三种相都是铁磁金属。特别是，{\alpha }-相的PtMnBi表现出高达802 K的TC和相对较大的Gilbert阻尼0.085。此外，{\gamma }-相的PtMnBi具有可忽略不计的AHC，在费米能级达到203{\Omega }-1cm-1。为了评估其在纳米尺度器件中的潜力，我们进一步研究了{\alpha }-相的PtMnBi薄膜。 吉尔伯特阻尼在{\alpha }相PtMnBi薄膜中随薄膜厚度变化，我们将其变化归因于高对称点{\Gamma }处不同的能带结构，这些结构来源于薄膜厚度的差异。 此外，1层（1L）{\alpha }相薄膜保持强铁磁性（TC = 688 K），并与体材料相比表现出增强的吉尔伯特阻尼（0.14）和AHC（1116{\Omega }-1cm-1）。 有趣的是，在2%面内双轴压缩应变下，1L{\alpha }相PtMnBi薄膜的吉尔伯特阻尼增加到0.17，AHC达到2386{\Omega }-1cm-1。 巨吉尔伯特阻尼和大AHC的共存使{\alpha }相PtMnBi成为实际自旋电子学应用的有吸引力的平台，并突显了半Heusler合金在自旋电子器件设计中的潜力。 显示英文摘要

摘要： Half-Heusler alloys have emerged as promising candidates for novel spintronic applications due to their exceptional properties including the high Curie temperature (TC) above room temperature and large anomalous Hall conductivity (AHC). In this work, we systematically study the magnetic and electronic properties of PtMnBi in {\alpha}-, \{beta}-, and {\gamma}-phase using first-principles calculations and Monte Carlo simulations. The three phases are found to be ferromagnetic metals. In particular, the {\alpha}-phase PtMnBi shows a high TC up to 802 K and a relatively large Gilbert damping of 0.085. Additionally, the {\gamma}-phase PtMnBi possesses a non-negligible AHC, reaching 203 {\Omega}-1cm-1 at the Fermi level. To evaluate its potential in nanoscale devices, we further investigate the {\alpha}-phase PtMnBi thin films. The Gilbert dampings of {\alpha}-phase PtMnBi thin films varies with film thickness and we attribute this variation to the distinct band structures at the high-symmetry point {\Gamma}, which arise from differences in film thickness. Moreover, the 1-layer (1L) {\alpha}-phase thin film retains robust ferromagnetism (TC = 688 K) and shows enhanced Gilbert damping (0.14) and AHC (1116 {\Omega}-1cm-1) compared to the bulk. Intriguingly, under a 2% in-plane biaxial compressive strain, the Gilbert damping of 1L {\alpha}-phase PtMnBi thin film increases to 0.17 and the AHC reaches 2386 {\Omega}-1cm-1. The coexistence of giant Gilbert damping and large AHC makes {\alpha}-phase PtMnBi a compelling platform for practical spintronic applications, and highlights the potential of half-Heusler alloys in spintronic device design.