Pressure-induced superconductivity in quasi-one-dimensional ZrS 3

Due to their strong anisotropic and quasi-one-dimensional (1D) nature, transition metal trichalcogenides (TMTCs) $M{X}₃$ exhibit extraordinary electronic properties, such as charge density waves, superconducting transitions, and potentially a Luttinger liquid state. Rich quantum phenomena emerge under pressure, owing to enhanced interchain interactions, and exhibit strong dependencies on the elements $M$ and $X$. In this paper, we investigate structural phase transitions and the insulator-to-superconductor transition in highly insulating ${\mathrm{ZrS}}₃$ under pressures up to 119 GPa. A first-order isosymmetric transition occurs above 16 GPa, companying by a sudden reduction in the band gap due to the breaking of S-S bonds within the 1D chains and the formation of S-S bonds between chains. Superconducting behavior is observed starting at 63 GPa, with ${T}_c$ increasing under pressure and reaching 9.1 K at 119 GPa. Our findings provide insights into the high-pressure electronic properties of insulating ${\mathrm{ZrS}}₃$ and stimulate further exploration of emergent phenomena in other low-dimensional material systems.