AI 中文总结
研究通过多种测量对 Kagome 金属 LuNb6Sn6 进行 dHvA 研究，确定量子振荡频率等，发现 CDW 转变及非平凡贝里相位，计算电子参数和结构，揭示其 FS 拓扑与电子结构，为理解 Kagome 材料电子性质提供新见解。
AI 中文摘要
我们报告了一项对最近发现的 Kagome 金属 LuNb6Sn6 的详细德哈斯 - 范阿尔芬（dHvA）研究，使用了扭矩磁强计、磁化和热容量测量。温度相关的扭矩和热容量数据揭示了在 T_CDW = 85 K 处的电荷密度波（CDW）转变，测量中观察到的热滞表明转变是一级的。量子振荡测量确定了两个主要的 dHvA 频率：F_alpha ~ 20 T 和 F_beta ~ 200 T，其角度依赖性与椭球形费米面（FS）口袋一致。朗道扇图分析揭示了与 F_alpha 口袋相关的非平凡贝里相位的证据，表明 LuNb6Sn6 中可能存在非平凡电子拓扑。使用 Lifshitz - Kosevich 公式对振荡的温度和磁场依赖性分析得出表明各向异性量子输运性质的电子参数。第一性原理计算进一步深入了解电子结构，揭示了狄拉克型能带交叉、一个平带以及费米能级附近的多个范霍夫奇点。基于原始相的计算不能完全重现实验观察到的量子振荡频率，表明 CDW 诱导的 FS 重构在 LuNb6Sn6 的基态电子结构中起关键作用。这些结果为 LuNb6Sn6 的 FS 拓扑和电子结构提供了新的见解，丰富了我们对 Kagome 材料电子性质的理解。
英文摘要
We report a detailed de Haas-van Alphen (dHvA) study of the recently discovered kagome metal LuNb6Sn6 using torque magnetometry, magnetization, and heat-capacity measurements. Temperature-dependent torque and heat-capacity data reveal a charge density wave (CDW) transition at T_CDW = 85 K. The thermal hysteresis observed in both measurements establishes the first-order nature of the transition. Quantum oscillation measurements identify two major dHvA frequencies: F_alpha ~ 20 T and F_beta ~ 200 T, and their angular dependence is consistent with ellipsoidal Fermi surface (FS) pockets. Landau fan diagram analysis reveals evidence for a nontrivial Berry phase associated with the F_alpha pocket, indicating possible nontrivial electronic topology in LuNb6Sn6. Analysis of the temperature and magnetic field dependence of the oscillations using the Lifshitz-Kosevich formula yields electronic parameters that indicate anisotropic quantum transport properties. First-principles calculations provide further insight into the electronic structure, revealing Dirac-like band crossings, a flat band, and multiple van Hove singularities near the Fermi level. Our calculations based on the pristine phase cannot fully reproduce the experimentally observed quantum oscillation frequencies, suggesting that CDW-induced FS reconstruction plays a crucial role in the ground-state electronic structure of LuNb6Sn6. These results provide new insight into the FS topology and electronic structure of LuNb6Sn6, enriching our understanding of the electronic properties of kagome materials.
Comments25 pages, 10 figures, and 1 Table
