Wu Xianxin, Schwemmer Tilman, Müller Tobias, Consiglio Armando, Sangiovanni Giorgio, Di Sante Domenico, Iqbal Yasir, Hanke Werner, Schnyder Andreas P, Denner M Michael, Fischer Mark H, Neupert Titus, Thomale Ronny
Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China.
Phys Rev Lett. 2021 Oct 22;127(17):177001. doi: 10.1103/PhysRevLett.127.177001.
The recent discovery of AV_{3}Sb_{5} (A=K,Rb,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 AV_{3}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 AV_{3}Sb_{5}.
最近对AV₃Sb₅（A = K、Rb、Cs）的发现揭示了一个关于戈薇金属中奇异费米面不稳定性的有趣领域。其中，在多个范霍夫奇点附近发现了超导性，表现出非常规配对的迹象。我们表明，亚晶格干涉机制是理解戈薇金属中超导性形成的核心。从为AV₃Sb₅选择的一个合适的具有靠近费米能级的多个范霍夫奇点的最小紧束缚模型出发，我们对超导不稳定性进行了随机相位近似分析。非局域库仑排斥、范霍夫能带的亚晶格分布以及相互作用强度被证明是决定首选配对对称性的关键参数。讨论了对潜在拓扑表面态的影响，并提出了额外的测量建议，以确定AV₃Sb₅中超导性的本质。
