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...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).展开更多
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)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB28000000 and XDB33000000)the New Cornerstone Investigator Programthe 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)。
文摘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).
