The nature of the CDW in Kagome Superconductors AV3Sb5 from the perspective of electronic structure

ORAL

Abstract

The recently discovered layered kagome metals AV3Sb5 (A=K, Rb, Cs) have attracted much attention because of their unique combination of superconductivity, charge density wave (CDW) order, and nontrivial band topology. The CDW order with an in-plane 2x2 reconstruction is found to exhibit exotic properties, such as time-reversal symmetry breaking and rotational symmetry breaking. However, the nature of the CDW, including its dimensionality, structural pattern, and effect on electronic structure, remains elusive despite intense research efforts. Here, we present a comprehensive study on the electronic structure of AV3Sb5 by combining angle-resolved photoemission spectroscopy with Density Functional theory calculations. Apart from the energy shift of van Hove singularities, we observe doubleband splittings for V d-orbital bands in the CDW phase, which provides essential information for revealing the dimensionality and pattern of the CDW order. Our calculations show that three-dimensional CDW orders containing stacking of Star-of-David and Tri-Hexagonal patterns along the c axis can quantitatively reproduce the experimental features. These results provide crucial insights into the nature and distortion pattern of the CDW order, and its signature in the electronic structure, thereby laying down the basis for a substantiated understanding of the exotic properties in the family of AV3Sb5 kagome metals.

*The work at PSI was supported by the Swiss National Science Foundation under Grant. No. 200021-188413, and the Sino-Swiss Science and Technology Cooperation (Grant No. IZLCZ2-170075). The work at UC Santa Barbara was supported via the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMAIE-i program under award DMR-1906325. This research made use of the shared facilities of the NSF Materials Research Science and Engineering Center at UC Santa Barbara (DMR- 1720256). B. R. O. acknowledges support from the California NanoSystems Institute through the Elings Fellowship program.

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Publication: Nat Commun 13, 2220 (2022)
arXiv:2201.06477 (2002)

Presenters

  • Yong Hu

    • Paul Scherrer Institute

Authors

  • Xianxin Wu

    • Institute of Theoretical Physics,Chinese Academy of Sciences
    • Institute of theoretical physics, Chinese Academy of Sciences
    • Max Planck Institute for Solid State Phy

  • Yong Hu

    • Paul Scherrer Institute

  • Brenden Ortiz

    • University of California, Santa Barbara

  • Nicholas C Plumb

    • Paul Scherrer Institute

  • Stephen D Wilson

    • University of California, Santa Barbara

  • Andreas P Schnyder

    • Max Planck Institute for Solid State Research
    • Max Planck Institute for Solid State Physics

  • Ming Shi

    • Paul Scherrer Institute