We observed a pressure-induced semiconductor-metal transition, which was followed by the emergence of superconductivity in the nonsymmorphic topological insulator KHgAs. The superconducting transition temperature reaches a maximum of approximately 6.6 K at 31.8 GPa, after which it slightly decreases up to 55 GPa. We identified the pressure-induced phase transitions and determined the structures of three high-pressure phases of KHgAs through structure prediction. Our findings establish the high-pressure phase diagram of the hourglass fermion compound KHgAs and demonstrate the potential coexistence of superconductivity with a topologically nontrivial feature protected by nonsymmorphic symmetries.
- Guangyang Dai
- Yating Jia
- Changqing Jin
