Recently, topological insulators (TIs) KHgX (X = As, Sb, Bi) with hourglass-shaped dispersion have attracted great interest. Different from the TIs protected by either time-reversal or mirror crystal symmorphic symmetry tested in previous experiments, these materials were proposed as the first material class whose band topology relies on nonsymmorphic symmetries. As a result, KHgX shows many exotic properties, such as hourglass-shaped electronic channels and three-dimensional doubled quantum spin Hall effects. To date, high-pressure experimental studies on these nonsymmorphic TIs are minimal. Here, we carried out high-pressure electrical measurements up to 55 GPa, together with high-pressure X-ray diffraction measurements and high-pressure structure prediction on KHgAs. We found a pressure-induced semiconductor-metal transition between ~16 and 20 GPa, followed by the appearance of superconductivity with a T_c of ~3.5 K at approximately 21 GPa. The superconducting transition temperature was enhanced to a maximum of ~6.6 K at 31.8 GPa and then slowly decreased until 55 GPa. Furthermore, three high-pressure phases within 55 GPa were observed, and their crystal structures were established. Our results showed the high-pressure phase diagram of KHgAs and determined the pressure-induced superconductivity in nonsymmorphic TIs. Thus, our study can be used to facilitate further research on superconductivity and topologically nontrivial features protected by nonsymmorphic symmetries.

最近，具有沙漏形色散的拓扑绝缘体（TI）KHgX（X = As、Sb、Bi）引起了人们的极大兴趣。与之前实验中测试的受时间反转或镜面晶体对称性保护的TI不同，这些材料被认为是第一个能带拓扑依赖于非对称性的材料类别。因此，KHgX 显示出许多奇特的特性，例如沙漏形电子通道和三维双量子自旋霍尔效应。迄今为止，对这些非同态 TI 的高压实验研究还很少。在这里，我们进行了高达 55 GPa 的高压电测量，以及对 KHgAs 的高压 X 射线衍射测量和高压结构预测。T _c约为 3.5 K，压力约为 21 GPa。超导转变温度在 31.8 GPa 时最高升至约 6.6 K，然后缓慢下降直至 55 GPa。此外，还观察到了55 GPa以内的三个高压相，并建立了它们的晶体结构。我们的结果显示了 KHgAs 的高压相图，并确定了非对称 TI 中的压力诱导超导性。因此，我们的研究可用于促进对超导性和受非对称性保护的拓扑非平凡特征的进一步研究。