Orbital-selective superconductivity in the pressurized bilayer nickelate La3Ni2O7: An infinite projected entangled-pair state study

Abstract

The newly discovered high-Tc nickelate superconductor La3Ni2O7 has generated significant research interest. To uncover the pairing mechanism, it is essential to investigate the intriguing interplay between the two eg, i.e., dx2−y2 and dz2 orbitals. Here we conduct an infinite projected entangled-pair state (iPEPS) study of the bilayer t−J model, directly in the thermodynamic limit and with orbitally selective parameters for dx2−y2 and dz2 orbitals, respectively. The dx2−y2 electrons exhibit significant intralayer hopping t∥ (and spin couplings J∥) as well as strong interlayer J⊥ passed from the dz2 electrons. However, the interlayer t⊥ is negligible in this case. In contrast, the dz2 orbital demonstrates strong interlayer t⊥ and J⊥, while the inherent intralayer t∥ and J∥ are small. Based on the iPEPS results, we find clear orbital-selective behaviors in La3Ni2O7. The dx2−y2 orbitals exhibit robust superconductive (SC) order driven by the interlayer coupling J⊥, while the dz2 band shows relatively weak SC order as a result of small t∥ (lack of coherence) but large t⊥ (strong Pauli blocking). Furthermore, by substituting rare-earth element Pm or Sm with La, we find an enhanced SC order, which opens up a promising avenue for discovering nickelate superconductors with even higher Tc.

Source-reported materials — not catalogue approval

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