论文标题
电子相关性在Kagome晶格超导体Larh $ _3 $ b $ _2 $中的作用
Role of electronic correlations in the Kagome lattice superconductor LaRh$_3$B$_2$
论文作者
论文摘要
larh $ _3 $ b $ _2 $在分层结构中结晶，其中rh原子形成完美的kagome晶格。该材料以$ T_C \约2.6 $ 〜K \@显示超导性，并且密度波不稳定性没有签名。我们报告了在正常和超导状态下电子传输，磁化和热容量的测量，并得出了正常和超导参数。从电子带结构的第一原理计算中，我们确定了Kagome带的所有特征，主要由Rh $ d $ orbitals形成：平坦的乐队，Dirac Cones和Van Hove Singularies。声子分散剂和电子音波耦合的计算表明，LarH $ _3 $ b $ _2 $和AV $ _3 $ SB $ _5 $（a = k，cs，rb）之间的相似之处很强。对于Larh $ _3 $ b $ _2 $，它与观察到的$ T_C $定量匹配，支持常规的声子介导的配对机制。与$ a $ v $ _3 $ sb $ _5 $ family相比，我们猜想降低了电子相关性的重要性，而larh $ _3 $ b $ _2 $。
LaRh$_3$B$_2$ crystallizes in a layered structure where Rh atoms form a perfect Kagome lattice. The material shows superconductivity at $T_c \approx 2.6$~K\@ and no signature for density wave instabilities. We report our measurements of electronic transport, magnetization, and heat capacity in the normal and superconducting state, and derive normal and superconducting parameters. From first principles calculations of the electronic band structure, we identify all features of Kagome bands predominantly formed by the Rh $d$ orbitals: a flat band, Dirac cones, and van Hove singularities. The calculation of the phonon dispersions and electron-phonon coupling suggests a strong similarity between LaRh$_3$B$_2$ and AV$_3$Sb$_5$ (A=K,Cs,Rb). For LaRh$_3$B$_2$, it matches quantitatively with the observed $T_c$, supporting a conventional phonon mediated pairing mechanism. By comparison to the $A$V$_3$Sb$_5$ family, we conjecture a reduced importance of electron correlations in LaRh$_3$B$_2$.
