Concurrent Pressure-Enhanced Magnetic Order and Photoconductivity in Quasi-One-Dimensional Antiferromagnet MnSb₂S₄

Low-dimensional van der Waals materials constitute fertile ground for exploring intertwined magnetism, transport, and optoelectronics, yet the structural provenance underlying the interplay among diverse quantum orders remains scarcely elucidated. Here, we report a rare case of simultaneous enhancement of magnetic order and photoconductivity in pressurized quasi-one-dimensional antiferromagnet MnSb₂S₄. Concomitant with a pressure-induced insulator-to-metal transition, MnSb₂S₄ exhibits a collapse of magnetic order and dramatic positive-to-negative photoconductivity switching at ∼30 GPa. Notably, possible superconductivity emerges with further compression. Detailed structural analyses and theoretical calculations corroborate these anomalous behaviors and unravel sequential pressure-driven orbital and spin crossover of Mn²⁺, accompanied by opposite evolutions of Jahn-Teller distortions in two inequivalent [MnS₆] octahedra. The intriguing electronic and structural evolutions establish MnSb₂S₄ as a promising candidate for versatile device engineering and offer an ideal platform for deciphering intricate coupling among multiple degrees of freedom.