具有赝自旋- $1/2$ Yb $^{3+}$离子的完美三角形晶格的Yb基磁体已经成为实现量子自旋液体状态的候选者，NaYbS $_2$是突出的例子。在这里，我们提出了固溶体系列NaYb $_{1-x}$ Lu $_{x}$ S $_2$在整个替代范围$0\le x\le 1$具有良好定义的单晶。化学和结构分析表明Yb $^{3+}$被Lu $^{3+}$离子的统计上均匀的替代。我们用电子自旋共振（ESR）对相对较小的单晶进行了磁性表征。低于$30$ K的ESR强度可以很好地描述的居里-外斯函数的所有\textit{x}，随着降低外斯温度增加的Lu含量。这种减少的平均磁相互作用后，Lu取代也支持磁化测量。重要的是，对于任何$x$，在$2$ K以下都没有检测到磁性或自旋玻璃有序的迹象。对于$x>0.5$的ESR线宽强烈增加，表明分裂的磁系统成不连续的集群从渗流物理预期。实验磁化数据被发现是在良好的协议，所有$x$与经典的Monte Carlo模拟结果的三角晶格海森堡模型，修正了一个小的第二邻居相互作用。两者合计，我们的研究结果建立了NaYb $_{1-x}$ Lu $_{x}$ S $_2$作为一个家庭的稀释三角晶格自旋液体。
英文摘要：
Yb-based magnets, with a perfect triangular lattice of pseudospin-$1/2$ Yb$^{3+}$ ions, have emerged as candidates for realizing a quantum spin-liquid state, with NaYbS$_2$ being a prominent example. Here we present the solid-solution series NaYb$_{1-x}$Lu$_{x}$S$_2$ with well-defined single crystals over the entire substitution range $0\le x\le 1$. Chemical and structural analysis indicate a statistically homogeneous replacement of Yb$^{3+}$ by Lu$^{3+}$ ions. We magnetically characterize the relatively small single crystals using electron spin resonance (ESR). Below $30$K the ESR intensity can be well described by a Curie-Weiss function for all \textit{x}, with a decreasing Weiss temperature with increasing Lu content. This reduction of the average magnetic interaction upon Lu substitution is also supported by magnetization measurements. Importantly, no signs of magnetic or spin-glass order are detected down to $2$K for any $x$. For $x>0.5$ the ESR linewidth strongly increases, indicating the breakup of the magnetic system into disconnected clusters as expected from percolation physics. The experimental magnetization data are found to be in good agreement for all $x$ with results of classical Monte-Carlo simulations for a triangular-lattice Heisenberg model, amended with a small second-neighbor interaction. Taken together, our results establish NaYb$_{1-x}$Lu$_{x}$S$_2$ as a family of diluted triangular-lattice spin liquids.
Spectrum and low-temperature bulk properties of triangular quantum spin liquid candidate NaYbSe$_2$
Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；National High Magnetic Field Laboratory, Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室国家高磁场实验室）；University of California, Berkeley（加州大学伯克利分校）；University of Tennessee, Knoxville（田纳西大学诺克斯维尔分校）；National High Magnetic Field Laboratory, Florida State University（佛罗里达州立大学国家高磁场实验室）；Oak Ridge National Laboratory（橡树岭国家实验室）；Lanzhou University（兰州大学）；Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；Shanghai Jiao Tong University（上海交通大学）；University of Florida（佛罗里达大学）
Anisotropic magnetism and spin fluctuations in the triangular-lattice spin-liquid candidate NaYbSe$_2$: a single-crystal $^{23}$Na and $^{77}$Se NMR study
