中国物理B ›› 2025, Vol. 34 ›› Issue (11): 117101-117101.doi: 10.1088/1674-1056/adfef6

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Structure and superconductivity of La2PrNi2O7 under pressure

Qing Tian(田清)†, Denghui Zhu(朱登辉)†, and Wei Zhang(张微)‡   

  1. Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China
  • 收稿日期:2025-02-26 修回日期:2025-08-25 接受日期:2025-08-26 发布日期:2025-10-30
  • 基金资助:
    This work is supported by the National Key Research and Development Program of China (Grant No. 2023YFA1406103), the Education Department of Jilin Province, and Science and Technology Plan (Grant No. JJKH20211042KJ).

Structure and superconductivity of La2PrNi2O7 under pressure

Qing Tian(田清)†, Denghui Zhu(朱登辉)†, and Wei Zhang(张微)‡   

  1. Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China
  • Received:2025-02-26 Revised:2025-08-25 Accepted:2025-08-26 Published:2025-10-30
  • Contact: Wei Zhang E-mail:zhangw_bxx@jlu.edu.cn
  • Supported by:
    This work is supported by the National Key Research and Development Program of China (Grant No. 2023YFA1406103), the Education Department of Jilin Province, and Science and Technology Plan (Grant No. JJKH20211042KJ).

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摘要： Nickel-based superconductors have attracted great attention due to the finding of the Ruddlesden–Popper (R–P) bilayer nickelate La3Ni2O7 with superconducting critical temperature (Tc) of 80 K at pressure above 14 GPa. Recent efforts have been devoted to the study of La2PrNi2O7, while the detailed structure remains unclear. In this work, we explore the stability and physical properties of such an interesting system by using density functional theory and the U parameter simulation method implemented in VASP. The results show that the enthalpy of La2PrNi2O7is slightly larger than its parent material bilayer R–P nickelate La3Ni2O7. The electronic structure analysis indicates that near the Fermi level, the eg orbit of Ni dominates and strongly hybridizes with the 2p orbit of O, thereby forming a significant van Hove singularity that is conducive to superconductivity. The Amam phase to the I4/mmm phase occurs, accompanied by an increase in the bandwidth of Ni 3d z2 and an enhancement of the bonding–antibonding splitting (from about 0.5 eV to 1.5 eV), which leads to an increase in the density of states at the Fermi level. Our findings provide insights into the preparation and superconductivity of R–P bilayer nickelate.

关键词: hole-doping, superconductivity

Abstract: Nickel-based superconductors have attracted great attention due to the finding of the Ruddlesden–Popper (R–P) bilayer nickelate La3Ni2O7 with superconducting critical temperature (Tc) of 80 K at pressure above 14 GPa. Recent efforts have been devoted to the study of La2PrNi2O7, while the detailed structure remains unclear. In this work, we explore the stability and physical properties of such an interesting system by using density functional theory and the U parameter simulation method implemented in VASP. The results show that the enthalpy of La2PrNi2O7is slightly larger than its parent material bilayer R–P nickelate La3Ni2O7. The electronic structure analysis indicates that near the Fermi level, the eg orbit of Ni dominates and strongly hybridizes with the 2p orbit of O, thereby forming a significant van Hove singularity that is conducive to superconductivity. The Amam phase to the I4/mmm phase occurs, accompanied by an increase in the bandwidth of Ni 3d z2 and an enhancement of the bonding–antibonding splitting (from about 0.5 eV to 1.5 eV), which leads to an increase in the density of states at the Fermi level. Our findings provide insights into the preparation and superconductivity of R–P bilayer nickelate.

Key words: hole-doping, superconductivity

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

  • 71.15.Mb
74.70.-b (Superconducting materials other than cuprates)