Pressure-induced ferroelectric-to-superconductor transition in SnPS3

Ferroelectricity and superconductivity are prominent yet distinct quantum phenomena; materials exhibiting both of these phenomena are rare and of great fundamental and practical interest. Here, combining ab initio calculations and in situ measurements, we show that ferroelectric ${\mathrm{SnPS}}_{3}$ turns into a superconductor under pressure at 31.7 GPa, accompanied by a structural phase transition. Electronic band structure calculations reveal a partial flat band near the Fermi energy in compressed ${\mathrm{SnPS}}_{3}$, suggesting correlation effects as a possible origin of the observed superconducting state. The discovery of a pressure-induced ferroelectric-to-superconductor transition in ${\mathrm{SnPS}}_{3}$ raises the prospect of establishing this intriguing quantum phenomenon among a large class of metal phosphorous trichalcogenides, thereby broadening the material basis to elucidate the underlying physics.