Two-dimensional superconductivity in single-band correlated 2H-type NbO2 layers
Two-dimensional superconductivity in single-band correlated 2H-type NbO2 layers
复制标题
单能带相关 2H 型 NbO2 层的二维超导性
DOI：
10.1103/physrevb.105.104504
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发表时间：
2022
影响因子：
3.7
通讯作者：
Ohtomo Akira
中科院分区：
文献类型：
--
作者：
Soma Takuto;Yoshimatsu Kohei;Horiba Koji;Kumigashira Hiroshi;Ohtomo Akira
氧化物超导体具有由共享边缘的三角棱柱组成的二维 (2D) 层。这种结构是一种独特的氧化物模拟型过渡金属二硫属化物（TMD），但其电子特性尚未受到任何重视。使用外延薄膜，我们发现了与别列津斯基-科斯特利茨-托勒斯转变相关的二维超导性和上临界场的大各向异性。与 TMD 相比，与温度无关的各向异性强烈表明单带超导性。相应地，同步辐射光电子能谱和密度泛函理论揭示的很大程度上孤立的单态可以用强配体场分裂来解释。这些结果表明，超导性发生在具有狭窄且相关的单能带的二维层中，让人想起铜酸盐中的超导性。我们的研究深入了解了哈伯德系统与二维三角晶格的非常规相关性。
The oxide superconductorhas two-dimensional (2D)layers consisting of edge-shared triangular prisms. This structure is a unique oxide analog to-type transition-metal dichalcogenides (TMDs), yet its electronic properties have not received any significant attention. Usingepitaxial films, we find the 2D superconductivity associated with the Berezinskii-Kosterlitz-Thouless transition and a large anisotropy of the upper critical field. The temperature-independent anisotropy strongly suggests single-band superconductivity, in contrast to TMDs. Correspondingly, the largely isolated singlestate revealed by synchrotron-radiation photoelectron spectroscopy and density functional theory is explained in terms of strong ligand field splitting. These results indicate that superconductivity inoccurs in 2Dlayers with a narrow and correlated single band, reminiscent of superconductivity in cuprates. Our study provides insight into the unconventional correlation in the Hubbard system with a 2D triangular lattice.