中国物理B ›› 2025, Vol. 34 ›› Issue (4): 47105-047105.doi: 10.1088/1674-1056/adbacc

所属专题: TOPICAL REVIEW — Moiré physics in two-dimensional materials

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Electronic structure and disorder effect of La3Ni2O7 superconductor

Yuxin Wang(王郁欣)1,2, Yi Zhang(张燚)3,4,†, and Kun Jiang(蒋坤)1,2,‡   

  1. 1 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China;
    3 Department of Physics and Institute for Quantum Science and Technology, Shanghai University, Shanghai 200444, China;
    4 Shanghai Key Laboratory of High Temperature Superconductors and International Center of Quantum and Molecular Structures, Shanghai University, Shanghai 200444, China
  • 收稿日期:2025-01-16 修回日期:2025-02-25 接受日期:2025-02-27 出版日期:2025-04-15 发布日期:2025-04-15
  • 通讯作者: Yi Zhang, Kun Jiang E-mail:zhangyi821@shu.edu.cn;jiangkun@iphy.ac.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. NSFC-12494590, NSFC-12174428, and NSFC-12274279), the New Cornerstone Investigator Program, and the Chinese Academy of Sciences Project for Young Scientists in Basic Research (Grant No. 2022YSBR-048).

Electronic structure and disorder effect of La3Ni2O7 superconductor

Yuxin Wang(王郁欣)1,2, Yi Zhang(张燚)3,4,†, and Kun Jiang(蒋坤)1,2,‡   

  1. 1 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China;
    3 Department of Physics and Institute for Quantum Science and Technology, Shanghai University, Shanghai 200444, China;
    4 Shanghai Key Laboratory of High Temperature Superconductors and International Center of Quantum and Molecular Structures, Shanghai University, Shanghai 200444, China
  • Received:2025-01-16 Revised:2025-02-25 Accepted:2025-02-27 Online:2025-04-15 Published:2025-04-15
  • Contact: Yi Zhang, Kun Jiang E-mail:zhangyi821@shu.edu.cn;jiangkun@iphy.ac.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. NSFC-12494590, NSFC-12174428, and NSFC-12274279), the New Cornerstone Investigator Program, and the Chinese Academy of Sciences Project for Young Scientists in Basic Research (Grant No. 2022YSBR-048).

摘要: Determining the electronic structure of La$_3$Ni$_2$O$_7$ is an essential step towards uncovering its superconducting mechanism. It is widely believed that the bilayer apical oxygens play an important role in the bilayer La$_3$Ni$_2$O$_7$ electronic structure. Applying the hybrid exchange-correlation functionals, we obtain a more accurate electronic structure of La$_3$Ni$_2$O$_7$ at its high-pressure phase, where the bonding $\mathrm{d}_{z^2}$ band is below the Fermi level owing to the apical oxygen. The symmetry properties of this electronic structure and its corresponding tight-binding model are further analyzed. We find that the antisymmetric part is highly entangled, leading to a minimal nearly degenerate two-orbital model. Then, the apical oxygen vacancies effect is studied using the dynamical cluster approximation. This disorder effect strongly destroys the antisymmetric $\beta$ Fermi surface, leading to the possible disappearance of superconductivity.

关键词: electronic structure, oxygen vacancies disorder, dynamical cluster approximation, bilayer superconducting nickelate

Abstract: Determining the electronic structure of La$_3$Ni$_2$O$_7$ is an essential step towards uncovering its superconducting mechanism. It is widely believed that the bilayer apical oxygens play an important role in the bilayer La$_3$Ni$_2$O$_7$ electronic structure. Applying the hybrid exchange-correlation functionals, we obtain a more accurate electronic structure of La$_3$Ni$_2$O$_7$ at its high-pressure phase, where the bonding $\mathrm{d}_{z^2}$ band is below the Fermi level owing to the apical oxygen. The symmetry properties of this electronic structure and its corresponding tight-binding model are further analyzed. We find that the antisymmetric part is highly entangled, leading to a minimal nearly degenerate two-orbital model. Then, the apical oxygen vacancies effect is studied using the dynamical cluster approximation. This disorder effect strongly destroys the antisymmetric $\beta$ Fermi surface, leading to the possible disappearance of superconductivity.

Key words: electronic structure, oxygen vacancies disorder, dynamical cluster approximation, bilayer superconducting nickelate

中图分类号:  (Electronic structure of disordered solids)

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