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arXiv 2212.02899cond-mat.supr-concond-mat.mtrl-scicond-mat.str-el
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电子关联在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$_2$

Savita Chaudhary, Shama, Jaskaran Singh, Armando Consiglio, Domenico Di Sante, Ronny Thomale, Yogesh Singh

摘要:

LaRh $_3$ B $_2$以层状结构结晶,其中Rh原子形成完美的Kagome晶格。该材料在$T_c \approx 2.6$ ~K处表现出超导性,没有密度波不稳定性的特征。我们报告我们的测量的电子输运,磁化强度和热容量在正常和超导状态,并得出正常和超导参数。从电子能带结构的第一性原理计算,我们确定主要由Rh $d$轨道形成的Kagome带的所有功能:一个平坦的带,狄拉克锥,和范霍夫奇点。声子色散和电子-声子耦合的计算表明LaRh $_3$ B $_2$和AV $_3$ Sb $_5$(A=K,Cs,Rb)之间有很强的相似性。对于LaRh $_3$ B $_2$,它与观察到的$T_c$定量匹配,支持传统的声子介导的配对机制。通过与$A$ V $_3$ Sb $_5$家族的比较,我们推测LaRh $_3$ B $_2$中电子相关的重要性降低。

英文摘要:

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$_2$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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