摘要
Motivated by the recent discovery of high-temperature superconductivity in bilayer La_(3)Ni_(2)O_(7) under pressure,we study its electronic properties and superconductivity due to strong electron correlation.Using the inversion symmetry,we decouple the low-energy electronic structure into block-diagonal symmetric and antisymmetric sectors.It is found that the antisymmetric sector can be reduced to a one-band system near half filling,while the symmetric bands occupied by about two electrons are heavily overdoped individually.Using the strong coupling mean field theory,we obtain strong superconducting pairing with B_(1g)symmetry in the antisymmetric sector.We propose that due to the spin-orbital exchange coupling between the two sectors,B_(1g)pairing is induced in the symmetric bands,which in turn boosts the pairing gap in the antisymmetric band and enhances the high-temperature superconductivity with a congruent d-wave symmetry in pressurized La_(3)Ni_(2)O_(7).
作者
蒋坤
汪自强
张富春
Kun Jiang;Ziqiang Wang;Fu-Chun Zhang(Beijing National Laboratory for Condensed Matter Physics,and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China;Department of Physics,Boston College,Chestnut Hill,MA 02467,USA;Kavli Institute of Theoretical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China;Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China)
基金
the National Key R&D Program of China(Grant No.2022YFA1403900)
the National Natural Science Foundation of China(Grant Nos.11888101,12174428,and 11920101005)
the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB28000000 and XDB33000000)
the New Cornerstone Investigator Program
the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.2022YSBR-048)
supported by the U.S.Department of Energy,Basic Energy Sciences(Grant No.DE-FG02-99ER45747)。
