Strain-Tuned Nodal Superconductivity in the Charge-Ordered Kagome Metal CsV_{3}Sb_{5}.

The nature of the superconducting pairing symmetry in the kagome metal CsV_{3}Sb_{5} and its relationship with the charge density wave (CDW) order are central unresolved issues. Here, we investigate the evolution of superconductivity in CsV_{3}Sb_{5} under in situ uniaxial pressure using ^{121}Sb nuclear quadrupole resonance (NQR). We find that tensile strain significantly enhances the superconducting transition temperature, T_{c}, while the CDW remains unchanged, demonstrating that superconductivity can be tuned independently of the bulk charge order. At a tensile strain of ϵ=+0.90%, the nuclear spin-lattice relaxation rate reveals a remarkable double transition: an upper transition at T_{c1}=3.6  K to a nodal gap state, and a lower one at T_{c2}=3.0  K characterized by a nodeless gap. These results evidence degenerate superconducting states with different gap symmetry in the kagome metal at ambient pressure which split under strain. Our Letter demonstrates a high tunability of superconductivity by uniaxial pressure.