Commensurate-to-incommensurate transition of charge-density-wave order and a possible quantum critical point in pressurized kagome metal CsV3Sb5

Clarifying the interplay between charge density waves (CDWs) and superconductivity is important in kagome metal CsV$_3$Sb$_5$, pressure ($P$) can play a crucial role. Here, we present $^{121/123}$Sb nuclear quadrupole resonance (NQR) measurements under hydrostatic pressures up to 2.43 GPa CsV$_3$Sb$_5$ single crystals. We demonstrate that CDW gradually changes from commensurate modulation with star-of-David (SoD) pattern an incommensurate one superimposed SoD Tri-hexagonal (TrH) stacking along $c$-axis. Moreover, linewidth $\delta\nu$ of $^{121/123}$Sb-NQR spectra increases cooling down $T_{\rm CDW}$, indicating appearance short-range order due fluctuations pinned by quenched disorders. The shows Curie-Weiss temperature dependence tends diverge at $P_{\rm c} \sim$ 1.9 GPa, suggesting quantum critical point (QCP) exists c}$ where maximum. For $P > P_{\rm c}$, spin are enhanced when suppressed. Our results suggest maximal related QCP presence prevent rapid decrease otherwise after completely