论文标题
原型kagome金属COSN中相关电子状态的温度依赖性
Temperature dependence of correlated electronic states in archetypal kagome metal CoSn
论文作者
论文摘要
六角形COSN是一种新发现的沮丧的kagome金属。它显示了几乎接近文本的平面频带和轨道选择性的dirac费米子，它们与其密切相关的Co-3 $ d $轨道主要相关。由于相关的电子状态很容易受到外部条件（例如化学掺杂，压力和温度）的调节，因此在温度下，这些Kagome衍生的电子带的命运成为一个有趣且未解决的问题。在这项工作中，我们试图通过密度功能理论与嵌入式动力学平均场理论一起研究六边形COSN的温度依赖性电子结构。我们发现，六边形COSN与环境状况下的莫特绝缘状态非常接近。特别关注其Co-3 $ d $电子状态在温度方面的演变。至少六个不同的温度（或能量尺度），即$ t^{*} $，$ t _ {\ text {flext {fl}} $，$ t _ {\ text {s1}} $（和$ t _ {\ t _ {\ text {s2}}}} $弄清楚。它们与“伪塔”状态的稳定，非富特液相的出现，中间自旋状态的发作（和完整），旋转液相的发生，轨道冷冻过渡的开始。
Hexagonal CoSn is a newly-discovered frustrated kagome metal. It shows close-to-textbook flat bands and orbital-selective Dirac fermions, which are largely associated with its strongly correlated Co-3$d$ orbitals. Because correlated electronic states are easily regulated by external conditions (such as chemical doping, pressure, and temperature), the fate of these kagome-derived electronic bands upon temperature becomes an interesting and unsolved question. In this work, we try to study the temperature-dependent electronic structures of hexagonal CoSn by means of the density functional theory in conjunction with the embedded dynamical mean-field theory. We find that hexagonal CoSn is in close proximity to a Mott insulating state at ambient condition. Special attention is devoted to the evolution of its Co-3$d$ electronic states with respect to temperature. At least six different temperatures (or energy scales), namely $T^{*}$, $T_{\text{FL}}$, $T_{\text{S1}}$ (and $T_{\text{S2}}$), $T_{\text{SF}}$, and $\bar{T}$, are figured out. They are related to stabilization of the "pseudogap" state, emergence of the non-Fermi-liquid phase, onset (and completeness) of the intermediate spin state, occurrence of the spin-frozen phase, beginning of the orbital freezing transition, respectively.
