AI 中文总结
研究无限层镍酸盐超导态，通过异质结构工程等方法，发现无阳离子取代的PrNiO₂有本征超导性，新超导态局限于3%额外空穴掺杂内，与约20%二价掺杂超导穹顶分离且有更强上临界场各向异性，揭示其独特超导物理。
AI 中文摘要
无限层镍酸盐被广泛视为铜酸盐类似物，超导性在其中出现并形成以10%-20%阳离子取代为中心的超导穹顶。本文表明，无阳离子取代的纯净化学计量比PrNiO₂在未封顶薄膜中表现出以零电阻和抗磁性为特征的本征超导性。通过异质结构工程，进一步排除了超导性的界面起源。值得注意的是，在三价取代的PrNiO₂中始终观察到零电阻超导性，而稀二价取代会迅速抑制它。结合角分辨光电子能谱研究，这些结果表明这种新的超导态局限于从纯净PrNiO₂额外空穴掺杂的3%以内。此外，该相在相图中通过一个非超导区域与先前建立的约20%二价掺杂的超导穹顶分开，并且其特征还在于明显更强的上临界场各向异性。这些发现建立了一个独特的分离超导态，表明无限层镍酸盐不仅是铜酸盐类似物，而且具有独特的超导物理。
英文摘要
Infinite-layer nickelates have been widely viewed as cuprate analogs in which superconductivity emerges and forms a superconducting dome centered around 10-20% cation substitution. Here we show that pristine and stoichiometric PrNiO2, without cation substitution, exhibits intrinsic superconductivity characterized by zero resistance and diamagnetism in uncapped films. Through heterostructure engineering, we further exclude an interfacial origin of the superconductivity. Remarkably, zero-resistance superconductivity is consistently observed in trivalent-substituted PrNiO2, whereas it is rapidly suppressed by dilute divalent substitution. Combined with angle-resolved photoemission studies, these results indicate that such a new superconducting regime is confined to within 3% additional hole doping from pristine PrNiO2. Furthermore, this phase is separated from the previously established superconducting dome around ~ 20% divalent doping by a non-superconducting region in the phase diagram, and is further distinguished by a remarkably stronger upper-critical-field anisotropy. These findings establish a unique separated superconducting regime, suggesting that infinite-layer nickelates are not merely cuprate analogs but host distinct superconducting physics.
Comments7 pages, 4 figures
