2025/08/06 by Mo, Shi-cong, Zheng, Yao-yuan, Wú, Wéi
#FOS: Physical sciences #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2508.04554
The mechanism of superconductivity in La3Ni2O7 bulk and film superconductors remains actively debated. Here, we investigate the bilayer two-orbital Kanamori-Hubbard model for La3Ni2O7 using cellular dynamical mean-field theory. We discover two intertwined s±- wave superconductivities with distinct physical origins. We show that when the dz2 orbital is under-doped, electron pairing associated to Hund's coupling JH prevails. As dz2 hole-doping δz increases, a second superconductivity, which is largely insensitive to JH but exhibiting a critical reliance on the dz2 - dx2-y2 hybridization V, arises. These two primary pairing states exhibit comparable maximum transition temperatures Tc, and evolve from one to the other following a smooth Tc versus δz relation. A stark particle-hole asymmetry is observed in the superconducting phase diagram, indicating the crucial role played by the γ- band of dz2 orbital in pairing. Our results present a picture unifying the two possible pairing mechanisms in La3Ni2O7 superconductors. We discuss the implications of our findings to recent experiments.