We report the evolution of nematic fluctuations in FeSe_1−xS_x single crystals as a function of Sulfur content x across the nematic quantum critical point (QCP) x_c ~ 0.17 via Raman scattering. The Raman spectra in the B_1g nematic channel consist of two components, but only the low energy one displays clear fingerprints of critical behavior and is attributed to itinerant carriers. Curie–Weiss analysis of the associated nematic susceptibility indicates a substantial effect of nemato-elastic coupling, which shifts the location of the nematic QCP. We argue that this lattice-induced shift likely explains the absence of any enhancement of the superconducting transition temperature at the QCP. The presence of two components in the nematic fluctuations spectrum is attributed to the dual aspect of electronic degrees of freedom in Hund’s metals, with both itinerant carriers and local moments contributing to the nematic susceptibility.

我们报告FESE向列波动的进化_{1- X}小号_X单晶作为硫含量的函数X横跨向列量子临界点（QCP）X _Ç  〜经由拉曼散射0.17。B _1g中的拉曼光谱向列通道由两个部分组成，但只有低能量的通道显示清晰的关键行为指纹，并归因于流动载体。对相关的向列磁化率的居里-魏斯分析表明，线虫-弹性耦合具有实质性影响，这会改变向列QCP的位置。我们认为，这种晶格引起的位移可能解释了QCP处超导转变温度没有任何增强。向列波动谱中两个成分的存在归因于洪德金属中电子自由度的双重方面，流动性载流子和局部矩都对向列磁化率起贡献。