Nature of Unconventional Pairing in the Kagome Superconductors AV<sub>3</sub>Sb<sub>5</sub> (A=K,Rb,Cs)
ORAL
Abstract
The recent discovery of AV3Sb5 (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 AV3Sb5, 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 AV3Sb5.
*This work is funded by the Deutsche Forschungsgemeinschaft(DFG, German Research Foundation) through Project-ID258499086—SFB 1170 and through the Würzburg-Dresden Cluster of Excellence on Complexity and Topologyin Quantum Matter—ct.qmat Project-ID 390858490—EXC2147. . I. acknowledges financial support by the Scienceand Engineering Research Board (SERB), Department ofScience and Technology (DST), India through the StartupResearch Grant No. SRG/2019/000056 and MATRICSGrant No. MTR/2019/00104. This research was supported in part bythe National Science Foundation under Grant No. NSF PHY-1748958. This project has received funding from theEuropean Research Council (ERC) under the EuropeanUnions Horizon 2020 research and innovation programm(ERC-StG-Neupert-757867-PARATOP). The research lead-ing to these results has received funding from the EuropeanUnions Horizon 2020 research and innovation programmeunder the Marie Skłodowska-Curie Grant AgreementNo. 897276.
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Publication:Phys. Rev. Lett. 127, 177001 (2021) (arXiv:2104.05671)
Presenters
Xianxin Wu
Max Planck Institute for Solid State Phy
Max Planck Institute for Solid State Research
Max Planck Institute for Solid State Physics
Authors
Xianxin Wu
Max Planck Institute for Solid State Phy
Max Planck Institute for Solid State Research
Max Planck Institute for Solid State Physics
Tilman Schwemmer
Institute for Theoretical Physics, University of Würzburg
Tobias Müller
Institute for Theoretical Physics, University of Würzburg
Armando Consiglio
Institute for Theoretical Physics, University of Würzburg
Giorgio Sangiovanni
Julius-Maximilians University of Wuerzbu
Julius-Maximilians University of Wuerzburg
Domenico Di Sante
University of Bologna
Center for Computational Quantum Physics, Flatiron Institute
