潜在的利夫希茨转换在阴性皮尼克提德Ba1-SrNi2As2中的最佳替代
Dushyant M Narayan1, Peipei Hao1, Rafał Kurleto1
1Center for Experiments on Quantum Materials, Department of Physics, University of Colorado, Boulder, CO 80309, USA.
Science advances
|October 18, 2023
概括
在BaNi2As2中替换Sr会抑制电荷顺序并增强超导性. 这与电子阴性波动和嵌套的费米口袋有关,类似于基于铁的超导体.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 超导电性 超导电性 超导电性
背景情况:
- 在结构上,BaNi2As2与BaFe2As2相似,BaNi2As2是一种具有电荷密度波 (CDW),内马性和超导性的超导体.
- 在BaNi2As2中Ba位点上的同价Sr替代抑制了CDW和阴性秩序.
- 替代导致超导过渡温度 (Tc) 的显著增强.
研究的目的:
- 研究Ba1-xSrxNi2As2.2中增强超导性的背后的机制.
- 了解电子秩序,费米表面拓和超导之间的关系.
主要方法:
- 高分辨率的角度分辨率光辐射光谱学 (ARPES) 测量.
- 密度函数理论 (DFT) 的计算.
- 电子带结构和费米表面拓学的分析.
主要成果:
- 根据ARPES的测量和DFT的计算,在整个替代范围中显示出良好的一致性.
- 在最佳 Sr 置换附近观察到一个 Lifshitz 过渡.
- 电子和具有Ni3d轨道特征的孔费米口袋在最佳替换时变得合理嵌套.
- 内马特波动得到增强,并与超导过渡相关.
结论:
- 由嵌套的Ni 3d费米口袋驱动的内马特波动被提议在Ba1-xSrxNi2As2.中增强超导性.
- 这些发现揭示了基和铁基超导体之间的联系.
- 这项研究为推动超导的非传统机制提供了洞察力.
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