Emergence of Double‐Dome Superconductivity in the Pressurized Dirac Semimetal BaMg ₂ Bi ₂

ABSTRACT Dirac semimetal is reported to be a unique topological material that manifests surface superconductivity that coexists with bulk band topology at ambient pressure. Here, we present a comprehensive investigation of high‐pressure superconducting properties in single crystal. Significantly, a pressure‐driven double‐dome superconducting behavior was revealed, with the superconducting transition temperature approaching the maximum values of 6.67 K at 4.5 GPa and 7.22 K at 10.4 GPa for the first and second superconducting domes, respectively. The combination of high‐pressure X‐ray diffraction, Hall resistivity measurements, and theoretical calculations demonstrates that, the first superconducting regime is closely related to the pressure‐modulated Lifshitz transition, whereas the second superconducting phase emerges concurrently with a structural transition from the ambient‐pressure phase to a high‐pressure phase.