Symmetry analysis shows orbital hybridization vanishes along the BZ diagonal, allowing the gap on alpha/beta pockets to test d_x2-y2 vs d_z2 dominance; experiments and RPA favor Hund's rule mechanism with full gap.
A unified theory of thin film and bulk bilayer nickelates
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
The discovery of bilayer nickelate superconductivity in both pressurized bulk and thin films has drawn enormous attention on their similarity and distinction. Here we provide a unified explanation based on the two-component scenario for a number of key experimental observations reported recently. Our theory predicts two superconducting domes upon electron or hole doping, separated by a valence bond state near $d_{z^2}$ half filling for strong interlayer superexchange coupling $J$, and a single dome across half filling with a lower $T_c$ for weak or moderate $J$. Increasing doping drives the normal state from a Fermi liquid to non-Fermi liquid or weak insulating behaviors, with quasi-linear-in-$T$ scattering rate near optimal $T_c$, while breaking the interlayer valence bonds by oxygen vacancies or chemical substitution simultaneously suppresses the superconductivity and causes local Kondo scattering of $d_{x^2-y^2}$ electrons. These explain the different superconducting transitions and normal states in bulk and thin films, the effect of $d_{z^2}$ hole or electron doping, and the Kondo effect in non-superconducting samples. We propose bulk superconductivity at ambient pressure by doping or reducing the interlayer magnetic coupling and predict even higher $T_c$ upon electron doping.
years
2026 2verdicts
UNVERDICTED 2representative citing papers
A two-component scenario unifies key observations in bilayer nickelate superconductivity, predicting doping-dependent superconducting domes and normal-state behaviors that differ by interlayer coupling strength.
citing papers explorer
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What Does the Single-Particle Spectrum Imply on the Pairing Nature and Pairing Mechanism in La$_3$Ni$_2$O$_7$?
Symmetry analysis shows orbital hybridization vanishes along the BZ diagonal, allowing the gap on alpha/beta pockets to test d_x2-y2 vs d_z2 dominance; experiments and RPA favor Hund's rule mechanism with full gap.
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A unified theory of thin film and bulk bilayer nickelates
A two-component scenario unifies key observations in bilayer nickelate superconductivity, predicting doping-dependent superconducting domes and normal-state behaviors that differ by interlayer coupling strength.