Daily Overview: The highlighted work today focuses on a theoretical study of interlayer superconductivity in a La3Ni2O7-inspired bilayer t-J-J⊥ ladder rather than on experimental observations; in this model, t is the in-plane electron hopping, J is the in-plane spin exchange, and J⊥ is the interlayer spin exchange. The authors use the density matrix renormalization group method, tune J⊥ over a large doping range δ=1/8–1/2, and construct a quantum phase diagram using spin-singlet pairing correlations as the main criterion. The theoretical results indicate that sufficiently large J⊥ can drive interlayer superconductivity in both Luther-Emery-liquid and Luttinger-liquid parent states: when two Luther-Emery liquids are coupled, in-plane superconductivity can transform into interlayer superconductivity either through an intermediate charge density wave (CDW) phase over a finite doping interval or directly, with this CDW phase evolving from the CDW state of the two-leg ladder at δ=1/4; when two Luttinger liquids are coupled, large J⊥ drives the system into interlayer superconductivity, whereas at intermediate J⊥ the in-plane Luttinger-liquid features remain stable, and the interlayer superconductivity exhibits enhanced quasi-long-range order with a power-law exponent Kzz_SC~1. Results for the three-layer ladder further indicate that strong J⊥ can stabilize interlayer superconductivity over a wider doping range, providing numerical evidence for understanding interlayer pairing in bilayer cuprates and nickelates. arXiv submission processing window: 2026-11-06 00:00 to 2026-11-06 00:00 UTC.

1. Evolution from intralayer to interlayer superconductivity in a bilayer $t$-$J$-$J_{\bot}$ ladder

Summary: This study uses the bilayer t-J-J⊥ ladder as a theoretical model (inspired by bilayer cuprate superconductors and La3Ni2O7), where t is the in-plane electron hopping, J is the in-plane spin exchange, and J⊥ is the interlayer spin exchange; using the density matrix renormalization group method, it tunes J⊥ over a wide doping range δ=1/8–1/2 and, with spin-singlet pairing correlations as the main criterion, constructs the quantum phase diagram of the bilayer two-leg ladder. The results show that sufficiently large J⊥ can drive interlayer superconductivity in two parent states, the Luther-Emery liquid and the Luttinger liquid: when two Luther-Emery liquids are coupled, in-plane superconductivity can transform into interlayer superconductivity either through an intermediate charge-density-wave (CDW) phase over a finite doping interval or directly, and this CDW phase likely develops from the CDW state of the two-leg ladder at δ=1/4; when two Luttinger liquids are coupled, large J⊥ drives the system into interlayer superconductivity, whereas at intermediate J⊥ the in-plane Luttinger-liquid features remain stable and interlayer superconductivity exhibits enhanced quasi-long-range order with power-law exponent Kzz_SC~1. Results for the three-leg ladder further indicate that strong J⊥ can stabilize interlayer superconductivity over a wider doping range, providing a numerical basis for understanding interlayer pairing in bilayer cuprates and nickelates.