FeSe is a unique high-T_ciron-based superconductor in which nematicity, superconductivity, and magnetism are entangled with each other in the P-T phase diagram. We performed ⁷⁷Se-nuclear magnetic resonance measurements under pressures of up to 3.9 GPa on 12% S-substituted FeSe, in which the complex overlap between the nematicity and magnetism are resolved. A pressure-induced Lifshitz transition was observed at 1.0 GPa as an anomaly of the density of states and as double superconducting (SC) domes accompanied by different types of antiferromagnetic (AF) fluctuations. The low-T_c SC dome below 1 GPa is accompanied by strong AF fluctuations, whereas the high-Tc SC dome develops above 1 GPa, where AF fluctuations are fairly weak. These results suggest the importance of the d_xy orbital and its intra-orbital coupling for the high-T_c superconductivity.

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