The interplay among magnetism, electronic nematicity, and superconductivity is the key issue in strongly correlated materials including iron-based, cuprate, and heavy-fermion superconductors. Magnetic fluctuations have been widely discussed as a pairing mechanism of unconventional superconductivity, but recent theory predicts that quantum fluctuations of nematic order may also promote high-temperature superconductivity. This has been studied in FeSe_1−xS_x superconductors exhibiting nonmagnetic nematic and pressure-induced antiferromagnetic orders, but its abrupt suppression of superconductivity at the nematic end point leaves the nematic-fluctuation driven superconductivity unconfirmed. Here we report on systematic studies of high-pressure phase diagrams up to 8 GPa in high-quality single crystals of FeSe_1−xTe_x. When Te composition x(Te) becomes larger than 0.1, the high-pressure magnetic order disappears, whereas the pressure-induced superconducting dome near the nematic end point is continuously found up to x(Te) ≈ 0.5. In contrast to FeSe_1−xS_x, enhanced superconductivity in FeSe_1−xTe_x does not correlate with magnetism but with the suppression of nematicity, highlighting the paramount role of nonmagnetic nematic fluctuations for high-temperature superconductivity in this system.

磁性，电子向列性和超导性之间的相互作用是强相关材料（包括铁基，铜酸盐和重费米子超导体）中的关键问题。磁涨落已被广泛讨论为非常规超导的配对机制，但最近的理论预测，向列级的量子涨落也可能促进高温超导。在FeSe _{1− x} S _x中已经对此进行了研究超导体表现出非磁性的向列和压力诱导的反铁磁顺序，但是在向列端点上突然抑制超导性，因此无法确定由向列波动驱动的超导性。在这里，我们对FeSe _{1- x} Te _x的高质量单晶中高达8 GPa的高压相图的系统研究进行了报道。当Te组成x（Te）大于0.1时，高压磁阶消失，而在向列终点附近的压力感应超导圆顶被连续发现直到x（Te）≈0.5。在对比FESE _{1- X}小号_X，增强在FESE超导_1-x Te _x与磁性无关，但与向列性的抑制无关，突显了非磁性向列波动对系统中高温超导性的重要作用。