Intertwined Short-Range Charge Correlations and Superconductivity in Sn-doped CsV₃Sb₅

The kagome metal CsV₃Sb₅ provides a unique platform to study the interplay between charge density wave (CDW) order and superconductivity. Hole doping via Sn substitution tunes the band filling, suppressing CDW formation and enhancing superconductivity in a characteristic double-dome phase diagram. We present a comprehensive investigation of charge correlations across the Sn-doped CsV₃Sb₅ series and their connection to the superconducting state. At low doping, the long-range 2 × 2 × 4 CDW order and associated superconducting fluctuations of the parent compound are rapidly suppressed. With further doping, the 2 × 2 × 2 CDW phase vanishes, giving rise to short-range quasi-1D correlations that persist throughout the second superconducting dome. As T_C decreases at higher doping, these correlations fade, suggesting that superconductivity in this regime relies on short-range charge order. We further propose a V-V dimer formation model within the kagome plane to describe these short-range correlations, where local rotational and translational symmetry breaking may play a key role in stabilizing the second superconducting dome.