Rotational symmetry breaking in the second superconducting dome of kagome system CsV₃Sb₅

Layered materials with a kagome lattice structure provide a rich platform to study electronic correlations and nontrivial topology. Among this group, CsV₃Sb₅ has attracted intense interest due to its rich phase diagram, which includes superconductivity, a 2a₀ × 2a₀ charge density wave (CDW) state, and a 4a₀ charge-stripe order that breaks rotational symmetry. Doping with Sn (substituting Sb sites) or Ti (substituting V sites) initially suppresses both charge orders and superconductivity, but subsequently induces a second superconducting dome. In this study, we investigate Sn- and Ti-substituted CsV₃Sb₅ within this second superconducting dome. Although the long-range charge orders are fully suppressed, we find evidence for local rotational symmetry breaking of the electronic structure in both Sn-doped and Ti-doped samples. These findings uncover a new aspect of symmetry breaking in the CsV₃Sb₅ phase diagram, revealing a tendency toward rotational symmetry breaking even without charge order, with potential implications for emergent superconductivity.