Pressure-induced phase transitions in GeSe are investigated from theory and experiment. Two new phases are predicted to exist in-between the well-known α-GeSe and the recently discovered β-GeSe under pressures. It is predicted that α-GeSe transforms into a rhombohedral structure with a space group of R3m and exhibits robust ferroelectricity at a low hydrostatic pressure. Laser-heated DAC experiments have been conducted to provide further evidence on the existence of the R3m phase. By increasing the hydrostatic pressure to approximately 6 GPa, the R3m phase is predicted to transform into a rock-salt crystal structure (\(Fm\bar 3m\)) and become a topological crystalline insulator.
- Hulei Yu
- Dexiang Gao
- Yue Chen
