Transition-metal dipnictide PtBi₂ exhibits rich structural and physical properties with topological semimetallic behavior and extremely large magnetoresistance (XMR) at low temperatures. We have investigated the electrical and magnetic properties of trigonal-phase PtBi_2-x single crystals with x ~ 0.4. Profound de Haas–van Alphen (dHvA) and Shubnikov-de Haas (SdH) oscillations are observed. Through fast Fourier transformation (FFT) analyses, four oscillation frequencies are extracted, which result from α, β, γ, and δ bands. By constructing the Landau fan diagram for each band, the Berry phase is extracted demonstrating the non-trivial nature of the α, β, and δ bands. Despite Bi deficiency, we observe the Zeeman splitting in dHvA and SdH oscillations under moderate magnetic field and the moderate Landé g factor (4.97–6.48) for the α band. Quantitative analysis of the non-monotonic field dependence including the sign change of the Hall resistivity suggests that electrons and holes in our system are not perfectly compensated thus not responsible for the XMR effect.

过渡金属二肽PtBi ₂具有丰富的结构和物理特性，具有拓扑半金属特性，并且在低温下具有极大的磁阻（XMR）。我们研究了具有x的三角相PtBi _{2 -x}单晶的电学和磁学性质 〜0.4。观察到了深的哈斯-范·阿尔芬（dHvA）和舒布尼科夫-德哈斯（SdH）振荡。通过快速傅立叶变换（FFT）分析，提取了四个振荡频率，它们是由α，β，γ和δ波段产生的。通过为每个频带构建Landau扇形图，可以提取Berry相，表明了α，β和δ频带的非平凡特性。尽管碧缺乏，我们观察到中度磁场和适度朗德在DHVA和SDH振荡塞曼分裂摹为α带宽因子（4.97-6.48）。对非单调场依赖性（包括霍尔电阻率的符号变化）的定量分析表明，我们系统中的电子和空穴没有得到完美补偿，因此对XMR效应不负责任。