The discovery of several electronic orders in kagome superconductors AV₃Sb₅ (A means K, Rb, Cs) provides a promising platform for exploring unprecedented emergent physics^{1,2,3,4,5,6,7,8,9}. Under moderate pressure (<2.2 GPa), the triple-Q charge density wave (CDW) order is monotonically suppressed by pressure, while the superconductivity shows a two-dome-like behaviour, suggesting an unusual interplay between superconductivity and CDW order^10,11. Given that time-reversal symmetry breaking and electronic nematicity have been revealed inside the triple-Q CDW phase^8,9,12,13, understanding this CDW order and its interplay with superconductivity becomes one of the core questions in AV₃Sb₅ (refs. ^3,5,6). Here, we report the evolution of CDW and superconductivity with pressure in CsV₃Sb₅ by ⁵¹V nuclear magnetic resonance measurements. An emergent CDW phase, ascribed to a possible stripe-like CDW order with a unidirectional 4a₀ modulation, is observed between P_c1 ≅ 0.58 GPa and P_c2 ≅ 2.0 GPa, which explains the two-dome-like superconducting behaviour under pressure. Furthermore, the nuclear spin-lattice relaxation measurement reveals evidence for pressure-independent charge fluctuations above the CDW transition temperature and unconventional superconducting pairing above P_c2. Our results not only shed new light on the interplay of superconductivity and CDW, but also reveal new electronic correlation effects in kagome superconductors AV₃Sb₅.

在 kagome 超导体 AV ₃ Sb ₅（A 表示 K、Rb、Cs）中发现了几个电子阶，为探索前所未有的新兴物理学^{1,2,3,4,5,6,7,8,9}提供了一个有前途的平台。在中等压力 (<2.2 GPa) 下，三Q电荷密度波 (CDW) 阶被压力单调抑制，而超导性显示出类似双圆顶的行为，表明超导性和 CDW 阶之间存在不寻常的相互作用^10,11 . 鉴于时间反转对称性破缺和电子向列性已在三Q CDW 相^{8,9,12,13中被揭示}，了解这种 CDW 阶及其与超导性的相互作用成为 AV ₃ Sb ₅中的核心问题之一（参考文献^3,5,6）。在这里，我们通过⁵¹ V 核磁共振测量报告了 CsV ₃ Sb _{5中 CDW 和超导性随压力的演变。}在P _c1 ≅  0.58 GPa 和P _c2 ≅之间观察到出现的 CDW 相，归因于具有单向 4a _{0调制的可能的条纹状 CDW 阶}   2.0 GPa，这解释了压力下的双圆顶状超导行为。此外，核自旋晶格弛豫测量揭示了 CDW 转变温度以上的与压力无关的电荷波动和P _c2以上的非常规超导配对的证据。我们的结果不仅揭示了超导性和 CDW 的相互作用，而且揭示了 kagome 超导体 AV ₃ Sb ₅中新的电子相关效应。