Lifshitz transition and superconductivity in Bi2S3 powder via interchain bonding under quasihydrostatic pressure

Abstract

Due to the quantum confinement effect, electrons in low-dimensional systems often display pronounced correlated effects, giving rise to various exotic electronic states such as charge density waves, Luttinger liquid states, and superconductivity. However, the electronic behavior in insulating quasi-one-dimensional materials is rarely explored. Here we report the pressure-driven Lifshitz insulator-metal transition and superconductivity in Bi2S3, which was reported to be a quasi-one-dimensional material, different from the two-dimensional sister compounds Bi2Se3 and Bi2Te3. Synchrotron x-ray diffraction and Raman spectroscopy confirm the stability of the original structure up to approximately 51 GPa. Notably, at around 21.8 GPa, Bi2S3 begins to exhibit metallic behavior across a broad temperature range due to the enhanced interchain interaction, evolving into a good metal by approximately 30.5 GPa. Above this critical pressure, we observe clear features of superconductivity, with the superconducting transition temperature (Tc) rising to approximately 3.7 K at 51.4 GPa. Ab initio calculations suggest that superconductivity in Bi2S3 arises from enhanced electron-phonon coupling, facilitated by a two-step bonding change following the Lifshitz insulator-metal transition around 30 GPa. While the compound shows an enhanced interchain interaction after the metallization, the electron density distribution shows a highly anisotropic behavior with a stronger conductive channel along a axis. This investigation provides a comprehensive understanding of the structural evolution and the underlying mechanisms of electron-phonon coupling induced superconductivity in Bi2S3. Our work provides a more intrinsic and clear phase diagram that perfectly explains the mechanism and greatly excludes the influence of nonhydrostatic conditions on the results. These insights are pivotal for advancing our understanding of topological phase transitions and superconductivity in analogous low-dimensional materials.

Source-reported materials — not catalogue approval

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