Electronic structure and disorder effect of La_(3)Ni_(2)O_(7)superconductor  

作　　者：Yuxin Wang Yi Zhang Kun Jiang 王郁欣;张燚;蒋坤

机构地区：[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

出　　处：《Chinese Physics B》2025年第4期63-69,共7页中国物理B(英文版)

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.NSFC-12494590,NSFC-12174428,and NSFC-12274279);the New Cornerstone Investigator Program;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 dz2 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 b Fermi surface,leading to the possible disappearance of superconductivity.

关 键 词：electronic structure oxygen vacancies disorder dynamical cluster approximation bilayer superconducting nickelate 

分 类 号：O469[理学—凝聚态物理]