标题： 调节凯尔文金属$RT_3$B$_2$中的电子关联性 显示英文标题

标题： Tuning electronic correlations in the Kagome metals $RT_3$B$_2$

摘要： $RT_3$B$_2$ ($R=$Y, Lu, $T=$ Co, Os) 系列包含由$T$原子组成的完美kagome晶格，为研究电子结构、超导性和晶格动力学之间的相互作用提供了一个有趣的平台。 在这里，我们比较了这个家族的两个成员，LuOs$_3$B$_2$和 YCo$_3$B$_2$，它们具有相似的晶体结构但化学组成不同，导致电子关联强度和自旋-轨道耦合效应的不同。 我们确认在LuOs$_3$B$_2$中存在超导性，其临界温度为$T_c = 4.75$K，而YCo$_3$B$_2$在1.8K以上仍不具有超导性。 第一性原理对LuOs$_3$B$_2$的电子-声子耦合的估计与其观察到的$T_c$一致，并表明耦合强度适中。 这两种材料都表现出由kagome衍生的电子特性，包括准平带、狄拉克锥和范霍夫奇点。 费米面计算显示，在YCo$_3$B$_2$中沿$c$轴表现出准一维行为，这与LuOs$_3$B$_2$更三维的费米面形成对比。 LuOs$_3$B$_2$的声子计算显示出虚模式，表明可能存在晶格不稳定。 实验估计的威尔逊比和卡多瓦基-伍兹比表明这两种化合物中存在显著的电子关联。 显示英文摘要

摘要： The $RT_3$B$_2$ ($R=$Y, Lu, $T=$ Co, Os) family hosts a perfect kagome lattice of $T$ atoms, offering an interesting platform to investigate the interplay of electronic structure, superconductivity, and lattice dynamics. Here, we compare two members of this family, LuOs$_3$B$_2$ and YCo$_3$B$_2$, with similar crystallography but differing chemical composition, leading to distinct electronic correlation strengths and spin-orbit coupling effects. We confirm superconductivity in LuOs$_3$B$_2$ with $T_c = 4.75$K, while YCo$_3$B$_2$ remains non-superconducting above 1.8K. First-principles estimates of the electron-phonon coupling for LuOs$_3$B$_2$ are consistent with its observed $T_c$ and suggest a moderate coupling strength. Both materials exhibit kagome-derived electronic features, including quasi-flat bands, Dirac cones, and van Hove singularities. Fermi surface calculations reveal quasi-one-dimensional behavior along the $c$-axis in YCo$_3$B$_2$, in contrast to the more three-dimensional Fermiology of LuOs$_3$B$_2$. Phonon calculations for LuOs$_3$B$_2$ show imaginary modes, indicating potential lattice instabilities. Experimental estimates of the Wilson and Kadowaki-Woods ratios point to non-negligible electronic correlations in both compounds.