Chemical substitution during growth is a well-established method to manipulate electronic states of quantum materials, and leads to rich spectra of phase diagrams in cuprate and iron-based superconductors. Here we report a novel and generic strategy to achieve nonvolatile electron doping in series of (i.e. 11 and 122 structures) Fe-based superconductors by ionic liquid gating induced protonation at room temperature. Accumulation of protons in bulk compounds induces superconductivity in the parent compounds, and enhances the T_c largely in some superconducting ones. Furthermore, the existence of proton in the lattice enables the first proton nuclear magnetic resonance (NMR) study to probe directly superconductivity. Using FeS as a model system, our NMR study reveals an emergent high-T_c phase with no coherence peak which is hard to measure by NMR with other isotopes. This novel electric-field-induced proton evolution opens up an avenue for manipulation of competing electronic states (e.g. Mott insulators), and may provide an innovative way for a broad perspective of NMR measurements with greatly enhanced detecting resolution.

生长过程中的化学取代是操纵量子材料电子态的行之有效的方法，并导致铜酸盐和铁基超导体中相图的丰富光谱。在这里，我们报告了一种新颖且通用的策略，通过离子液体门控在室温下诱导质子化，在一系列（即 11 和 122 结构）Fe 基超导体中实现非挥发性电子掺杂。质子在本体化合物中的积累导致母体化合物的超导性，并在某些超导化合物中大大增强_了Tc 。此外，晶格中质子的存在使第一个质子核磁共振 (NMR) 研究能够直接探测超导性。使用 FeS 作为模型系统，我们的 NMR 研究揭示了一个新兴的高T_{没有相干峰的c}相很难通过 NMR 与其他同位素一起测量。这种新颖的电场诱导质子演化为操纵竞争电子态（例如莫特绝缘体）开辟了一条途径，并可能为广泛的核磁共振测量提供一种创新方法，并大大提高检测分辨率。