The recent discovery of $A{\mathrm{V}}_3{\mathrm{Sb}}_5$ ($A=\mathrm{K},\mathrm{Rb},\mathrm{Cs}$) has uncovered an intriguing arena for exotic Fermi surface instabilities in a kagome metal. Among them, superconductivity is found in the vicinity of multiple van Hove singularities, exhibiting indications of unconventional pairing. We show that the sublattice interference mechanism is central to understanding the formation of superconductivity in a kagome metal. Starting from an appropriately chosen minimal tight-binding model with multiple van Hove singularities close to the Fermi level for $A{\mathrm{V}}_3{\mathrm{Sb}}_5$, we provide a random phase approximation analysis of superconducting instabilities. Nonlocal Coulomb repulsion, the sublattice profile of the van Hove bands, and the interaction strength turn out to be the crucial parameters to determine the preferred pairing symmetry. Implications for potentially topological surface states are discussed, along with a proposal for additional measurements to pin down the nature of superconductivity in $A{\mathrm{V}}_3{\mathrm{Sb}}_5$.

中文翻译：

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Kagome超导体AV3Sb5(A=K,Rb,Cs)中非常规配对的性质

最近发现的 $\mathrm{一种}{\mathrm{伏}}_3{锑}_5$ ($\mathrm{一种}=\mathrm{钾},铷,\mathrm{CS}$) 为 Kagome 金属中的奇异费米表面不稳定性发现了一个有趣的领域。其中，在多个范霍夫奇点附近发现了超导性，显示出非常规配对的迹象。我们表明，亚晶格干涉机制对于理解 Kagome 金属中超导性的形成至关重要。Starting from an appropriately chosen minimal tight-binding model with multiple van Hove singularities close to the Fermi level for$\mathrm{一种}{\mathrm{伏}}_3{锑}_5$，我们提供了超导不稳定性的随机相位近似分析。非局部库仑排斥、范霍夫带的亚晶格轮廓和相互作用强度是确定首选配对对称性的关键参数。讨论了对潜在拓扑表面状态的影响，并提出了额外测量的建议，以确定超导性的性质$\mathrm{一种}{\mathrm{伏}}_3{锑}_5$.