Appropriate theoretical framework for superconductivity in La3Ni2O7

Establish whether weak‑coupling Fermi‑surface–instability approaches (such as random phase approximation or functional renormalization group) or strong‑coupling correlation‑based models (such as t–J or valence‑bond theories) best describe the superconducting state in La3Ni2O7.

Background

Competing theoretical pictures have been advanced to explain high‑Tc superconductivity in La3Ni2O7, ranging from weak‑coupling treatments to strong‑coupling correlated models. Resolving which framework captures the physics is crucial for understanding pairing symmetry, the role of interlayer coupling, and the influence of electronic correlations.

The authors explicitly state that it remains unclear which theoretical description is most appropriate, highlighting the need to benchmark theory against the experimentally established Fermi surface and spectroscopic constraints.