Robust Fe divalent state in one-unit-cell FeSe/SrTiO3 thin films
Robust Fe divalent state in one-unit-cell FeSe/SrTiO3 thin films
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DOI：
10.1103/physrevb.106.245112
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发表时间：
2022-12
影响因子：
3.7
通讯作者：
Jingdong Shen;Wenxiang Jiang;F. Zhu;Guan-yong Wang;Huayao Li;G. Zhao;Qian Li;W. Yan;Wanli Yang;Y. Chuang;J. Jia;D. Qian;L. Wray;L. Miao
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文献类型：
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作者：
Jingdong Shen;Wenxiang Jiang;F. Zhu;Guan-yong Wang;Huayao Li;G. Zhao;Qian Li;W. Yan;Wanli Yang;Y. Chuang;J. Jia;D. Qian;L. Wray;L. Miao
轨道占有率作为Hund规则耦合的起源，为理解多轨道铁基超导体提供了重要信息。在超导温度高于60℃的衬底上生长的一单元(1UC)FeSe薄膜具有独特的电子结构和轨道占有率。本文介绍了不同厚度的FeSe/STO薄膜的X射线吸收光谱和共振非弹性X射线散射(RIXS)研究。结合原子多重态模拟分析，表明FeSe/STO薄膜(从1UC到10UC)具有与体相FeSe相同的纯电子构型。此外，在氧化过程中，1UC FeSe/STO明显比更厚的膜更持久地承载构型。讨论了1UC FeSe/STO的稳健性是衬底电荷转移的结果，以及维持高超导电性的机制。最后，我们的研究需要对原始超导薄膜1UC FeSe/STO进行进一步的高分辨率RIXS研究。
The orbital occupancy, as the origin of Hund's rule coupling, provides critical information in understanding the multiorbital iron-based superconductors. The one-unit-cell (1UC) FeSe thin film on asubstrate with superconductiveabove 60 K has been reported with unique electronic structures as well as orbital occupancy. In this paper, we present the x-ray absorption spectroscopy and resonant inelastic x-ray scattering (RIXS) study of the FeSe/STO thin films of different thicknesses. Together with the atomic multiplet simulation analysis, the FeSe/STO thin films (from 1UC to 10UC) are shown with the pureelectronic configuration which is identical to the bulk FeSe. Moreover, 1UC FeSe/STO is found to be distinctively more persistent in hosting theconfiguration other than the thicker films under the oxidization process. The robustness of thein 1UC FeSe/STO is discussed as a result of charge transfer from the substrate, as well as a mechanism to maintain the high-superconductivity. Finally, our research calls for a further high-resolution RIXS study of the pristine superconductive 1UC FeSe/STO thin film.