Orbital-selective electron correlations in multilayer nickelate superconductors

Motivated by the high temperature superconductivity of the bilayer nickelate La3Ni2O7 and trilayer nickelate La4Ni3O10 and the spectroscopic evidence of strong electron correlations in these compounds, we discuss the electron correlation effects in multilayer Hubbard models including the Ni 3d x2-y2 and z2 orbitals [1]. We show the normal state of the bilayer system to contain strong orbital-selective electron correlations, which causes orbital-dependent band renormalization and formation of interlayer singlets between electrons in the z2 orbitals. We also discuss the electron correlations in the trilayer nickelate La4Ni3O10, showing that a suitable trilayer Hubbard model exhibits strong layer and orbital selective correlations. These results provide a basis to understand the high temperature superconductivity in the multilayer nickelates.

Work is collaborated with Zhiguang Liao, Lei Chen, Yiming Wang, Guijing Duan and Qimiao Si.

Work at Renmin University was supported by the National Key R&D Program of China (Grant No. 2023YFA1406500), and the National Natural Science Foundation of China (Grant Nos. 12334008 and 12174441).
Work at Rice U. was primarily supported by the U.S. DOE, BES DE-SC0018197.

Reference: [1] Z. Liao et al., Phys. Rev. B 108, 214522 (2023)