高压狄拉克半金属BaMg2Bi2中双圆顶超导性的出现
Emergence of Double-Dome Superconductivity in the Pressurized Dirac Semimetal BaMg2Bi2
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中文总结 AI 辅助
本文研究高压下BaMg2Bi2单晶的超导性质，发现其存在压力驱动的双圆顶超导行为，第一超导圆顶Tc在4.5 GPa达6.67 K，第二在10.4 GPa达7.22 K，且两种超导相分别与Lifshitz转变、结构转变相关。
中文摘要 AI 辅助
据报道，狄拉克半金属BaMg2Bi2是一种独特的拓扑材料，在常压下表现出与体带拓扑共存的表面超导性。本文对BaMg2Bi2单晶的高压超导性质进行了全面研究，首次揭示了压力驱动的双圆顶超导行为：第一超导圆顶在4.5 GPa时超导转变温度Tc接近最大值6.67 K，第二超导圆顶在10.4 GPa时Tc接近最大值7.22 K。结合高压X射线衍射、霍尔电阻率测量和理论计算表明，第一超导区域与压力调制的Lifshitz转变密切相关，而第二超导相则与常压P3m1相向高压Pnma相的结构转变同时出现。
英文摘要
Dirac semimetal BaMg2Bi2 is reported to be a unique topological material that manifests surface superconductivity that coexistswith bulk band topology at ambient pressure. Here, we present a comprehensive investigation of high-pressure superconductingproperties in BaMg2Bi2 single crystal. Significantly, a pressure-driven double-dome superconducting behavior was revealed, withthe superconducting transition temperature Tc approaching the maximum values of 6.67 K at 4.5 GPa and 7.22 K at 10.4 GPafor the first and second superconducting domes, respectively. The combination of high-pressure X-ray diffraction, Hall resistivitymeasurements, 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 fromthe ambient-pressure P3m1 phase to a high-pressure Pnma phase.
