发表机构
University of West Georgia; University of California, Santa Barbara; National High Magnetic Field Laboratory; Florida State University（佐治亚西部大学; 加州大学圣塔芭芭拉分校; 国家高磁场实验室; 佛罗里达州立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过磁化与TDO测量及第一性原理计算，研究了kagome磁体HoV6Sn6的磁各向异性与多带费米面拓扑，确认铁磁基态及V-d轨道主导的低能电子性质。
AI 中文摘要
我们报道了利用磁化强度和隧道二极管振荡器（TDO）测量对kagome磁体HoV$_6$Sn$_6$的磁性质与费米面拓扑进行的研究。温度依赖的磁化强度在高温下表现出居里-外斯行为，并在$T_c$ $\approx$ 2.4 K以下揭示出长程磁有序。在Tc以下，场依赖的磁化强度显示出显著的磁各向异性，对于沿面外和面内方向施加的磁场，饱和磁矩分别约为9.5和7 $\mu_B$/Ho。为了探测费米面，我们在高达41.5 T的磁场和低至0.35 K的温度下进行了TDO测量。TDO信号展现出清晰的多频率量子振荡，频率最高可达$\sim$ 9 kT。角度依赖和温度依赖的测量分别用于确定费米面几何和回旋有效质量。为了阐明电子结构，我们进行了电子能带、态密度（DOS）和费米面的第一性原理计算。计算得到的能带结构在费米能级附近展现出平带特征、范霍夫奇点和类似狄拉克的交叉。费米能级附近的态密度主要由V-d轨道主导，表明V kagome层在决定HoV6Sn6的低能电子性质中起主要作用。我们的计算进一步支持Ho矩沿c轴取向的铁磁基态，与中子散射测量一致。根据HoV6Sn6费米面口袋计算得到的量子振荡频率与实验观测到的频率总体吻合良好。我们的实验与理论结合的结果为HoV$_6$Sn$_6$的磁各向异性和电子结构提供了见解，并揭示了其多带费米面拓扑。
英文摘要
We report a study of the magnetic properties and Fermi-surface topology of the kagome magnet HoV$_6$Sn$_6$ using magnetization and tunnel-diode-oscillator (TDO) measurements. The temperature-dependent magnetization exhibits Curie-Weiss behavior at high temperatures and reveals long-range magnetic order below $T_c$ $\approx$ 2.4 K. Below Tc, the field-dependent magnetization reveals pronounced magnetic anisotropy, with saturation moments of $\approx$ 9.5 and 7 $μ_B$ /Ho for fields applied along the out-of-plane and in-plane directions, respectively. To probe the Fermi surface, we perform TDO measurements in magnetic fields up to 41.5 T and at temperatures down to 0.35 K. The TDO signal exhibits well-defined quantum oscillations with multiple frequencies extending up to $\sim$ 9 kT. Angular- and temperature-dependent measurements are used to determine the Fermi-surface geometry and cyclotron effective masses, respectively. To elucidate the electronic structure, we perform first-principles calculations of the electronic bands, density of states (DOS), and Fermi surface. The calculated band structure exhibits flat-band features, van Hove singularities, and Dirac-like crossings near the Fermi level. The DOS near the Fermi level is dominated by the V-d orbitals, indicating that the V kagome layers play a major role in determining the low-energy electronic properties of HoV6Sn6. Our calculations further support a ferromagnetic ground state with the Ho moments oriented along the c axis, consistent with neutron-scattering measurements. The calculated quantum-oscillation frequencies from the Fermi-surface pockets of HoV6Sn6 are in overall good agreement with the experimentally observed frequencies. Our combined experimental and theoretical results provide insight into the magnetic anisotropy and electronic structure of HoV$_6$Sn$_6$ and reveal its multiband Fermi-surface topology.
Comments28 pages, 8 figures
