Half-Heusler compounds have attracted significant attention because of their topologically non-trivial electronic structure, which leads to unusual electron transport properties. We thoroughly investigated the magnetotransport properties of high-quality single crystals of two half-Heusler phases, TbPtBi and HoPtBi, in pursuit of the characteristic features of topologically non-trivial electronic states. Both studied compounds are characterized by the giant values of transverse magnetoresistance with no sign of saturation in magnetic field up to 14 T. HoPtBi demonstrates the Shubnikov-de Haas effect with two principal frequencies, indicating a complex Fermi surface; the extracted values of carrier effective masses are rather small, $0.18\,m_e$ and $0.27\,m_e$. The investigated compounds exhibit negative longitudinal magnetoresistance and anomalous Hall effect, which likely arise from a nonzero Berry curvature. Both compounds show strongly anisotropic magnetoresistance, that in HoPtBi exhibits a butterfly-like behavior.

中文翻译：

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半赫斯勒拓扑半金属候选物 TbPtBi 和 HoPtBi 中的异常霍尔效应和负纵向磁阻

Half-Heusler 化合物因其拓扑上非平凡的电子结构而引起了极大的关注，这导致了不寻常的电子传输特性。我们彻底研究了两个半赫斯勒相 TbPtBi 和 HoPtBi 的高质量单晶的磁传输特性，以追求拓扑非平凡电子态的特征。两种研究的化合物的特点是横向磁阻的巨大值，在高达 14 T 的磁场中没有饱和迹象。 HoPtBi 证明了具有两个主要频率的 Shubnikov-de Haas 效应，表明复杂的费米表面；载流子有效质量的提取值相当小，$0.18\,m_e$ 和 $0.27\,m_e$。研究的化合物表现出负纵向磁阻和反常霍尔效应，这可能是由非零贝里曲率引起的。两种化合物都表现出强烈的各向异性磁阻，在 HoPtBi 中表现出类似蝴蝶的行为。