Superconducting transition and topological behavior in π -SnS under high pressure

The interplay between superconductivity and topological properties has garnered significant research interest due to its potential implications for novel quantum materials. Here, we systematically investigate the structural, topological, and electronic transport properties of \ensuremath{\pi}-SnS nanocrystals under high pressure. A pressure-induced superconducting transition is observed at 30.4 GPa, characterized by a dome-shaped behavior with a maximum superconducting transition temperature $({T}_{\mathrm{c}})$ of 3.7 K, which persists up to 91 GPa. Synchrotron x-ray diffraction reveals two structural phase transitions: from $P{2}_{1}3\text{\ensuremath{-}}\mathrm{I}$ to $P{2}_{1}3\text{\ensuremath{-}}\mathrm{II}$ at 9.3 GPa, and subsequently to $Pm\overline{3}m$ at 44.8 GPa. Furthermore, theoretical calculations indicate that both novel high-pressure phases of SnS exhibit topological properties coexisting with superconductivity. The theoretical results reveal an evolution from trivial semiconductors to weak topological and ultimately to strong topological materials. Our findings suggest that \ensuremath{\pi}-SnS provides an excellent platform for exploring the interplay between superconductivity and the topological characteristics of electronic systems.