Electronic nature of charge density wave and electron-phonon coupling in kagome superconductor KV<sub>3</sub>Sb<sub>5</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35022418.
- Also identified by DOI 10.1038/s41467-021-27946-6 and PMC identifier 8755796.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The Kagome superconductors AV<sub>3</sub>Sb<sub>5</sub> (A = K, Rb, Cs) have received enormous attention due to their nontrivial topological electronic structure, anomalous physical properties and superconductivity. Unconventional charge density wave (CDW) has been detected in AV<sub>3</sub>Sb<sub>5</sub>. High-precision electronic structure determination is essential to understand its origin. Here we unveil electronic nature of the CDW phase in our high-resolution angle-resolved photoemission measurements on KV<sub>3</sub>Sb<sub>5</sub>. We have observed CDW-induced Fermi surface reconstruction and the associated band folding. The CDW-induced band splitting and the associated gap opening have been revealed at the boundary of the pristine and reconstructed Brillouin zones. The Fermi surface- and momentum-dependent CDW gap is measured and the strongly anisotropic CDW gap is observed for all the V-derived Fermi surface. In particular, we have observed signatures of the electron-phonon coupling in KV<sub>3</sub>Sb<sub>5</sub>. These results provide key insights in understanding the nature of the CDW state and its interplay with superconductivity in AV<sub>3</sub>Sb<sub>5</sub> superconductors.