We report on the single crystal growth and transport properties of a topological semimetal CaAgBi which crystallizes in the hexagonalABC-type structure with the non-centrosymmetric space groupP63mc(No. 186). The transverse magnetoresistance measurements with current in the basal plane of the hexagonal crystal structure reveal a value of about 30 % forI// [10-10] direction and about 50 % forI// [1-210] direction at 10~K in an applied magnetic field of 14~T. The magnetoresistance shows a cusp-like behavior in the low magnetic field region, suggesting the presence of weak antilocalization effect for temperatures less than 100~K. The Hall measurements reveal that predominant charge carriers are $p$-type, exhibiting a linear behavior at high fields. The magnetoconductance of CaAgBi is analysed based on the modified Hikami-Larkin-Nagaoka (HLN) model. Our first-principle calculations within a density-functional theory framework reveal that the Fermi surface of CaAgBi consists of both the electron and hole pockets and the size of the hole pocket is much larger than electron pockets suggesting the dominant $p$-type carriers in accordance with our experimental results.

中文翻译：

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非中心对称CaAgBi单晶的磁输运特性

我们报告了拓扑半金属 CaAgBi 的单晶生长和传输特性，该半金属 CaAgBi 在六边形 ABC 型结构中结晶，具有非中心对称空间群 P63mc（No. 186）。在六方晶体结构的基面中电流的横向磁阻测量显示，I// [10-10] 方向的值约为 30%，I//[1-210] 方向的值约为 50%，在 10~K 时外加磁场14~T。磁阻在低磁场区呈尖峰状，表明在低于 100~K 的温度下存在较弱的反局域效应。霍尔测量表明，主要的电荷载流子是 $p$ 型，在高场下表现出线性行为。基于改进的 Hikami-Larkin-Nagaoka (HLN) 模型分析 CaAgBi 的磁导。