Investigating the effects of nanoscale strain on the electronic structure and charge density waves in kagome superconductors AV₃Sb₅

Kagome superconductors AV₃Sb₅ (A = Cs, Rb, K) attracted tremendous interest in recent years for numerous exotic electronic phenomena observed in these materials, including density waves that break time-reversal symmetry and rotation symmetry, and unusual superconductivity. We use high-resolution scanning tunneling microscopy and spectroscopy to study the effects of nanoscale strain in CsV₃Sb₅ and KV₃Sb₅. Our results suggest that the 4a₀ charge stripe order in CsV₃Sb₅ can be completely suppressed by strain. We also find that the in-plane strain can modify the anisotropy of the 2a₀ × 2a₀ CDW peaks. Lastly, we reveal how strain modulates the charge density wave spectral gap at the Fermi level. Our experiments provide fresh insights into strain tunability of electronic states in kagome superconductors.