Evolution of charge correlations in the hole-doped kagome superconductor CsV_3−xTi_xSb₅

The interplay between superconductivity and charge correlations in the kagome metal CsV₃Sb₅ can be tuned by external perturbations such as doping or pressure. Here we present a study of charge correlations and superconductivity upon hole doping via Ti substitution on the V kagome sites in CsV_3−xTi_xSb₅ via synchrotron x-ray diffraction and scanning superconducting quantum interference device measurements. While the superconducting phase, as viewed via the vortex structure, remains conventional and unchanged across the phase diagram, the nature of charge correlations evolves as a function of hole doping from the first superconducting dome into the second superconducting dome. For Ti doping in the first superconducting dome, competing 2 × 2 × 2 and 2 × 2 × 4 supercells form within the charge density wave state and are suppressed rapidly with carrier substitution. In the second superconducting dome, no charge correlations are detected. Comparing these results to those observed for CsV₃Sb_5−xSn_x suggests important differences between hole doping via chemical substitution on the V and Sb sites, particularly in the disorder potential associated with each dopant.