Nodeless superconducting gap and electron-boson coupling in (La,Pr,Sm)(3)Ni(2)O(7) films
Summary
The discovery of superconductivity in Ruddlesden-Popper (RP) bilayer nickelate films under ambient pressure provides an opportunity to directly investigate electronic energy scales of the superconducting state and the pairing mechanism. We report angle-resolved photoemission spectroscopy measurements of superconducting (La,Pr,Sm)3Ni2O7 thin films by developing an ultra-high vacuum cryogenic sample quenching and transfer technique. A superconducting gap of ~18 meV with coherence peaks is ob
Content
# Nodeless superconducting gap and electron-boson coupling in (La,Pr,Sm)(3)Ni(2)O(7) films
*Published: 2026 May 21*
The discovery of superconductivity in Ruddlesden-Popper (RP) bilayer nickelate
films under ambient pressure provides an opportunity to directly investigate
electronic energy scales of the superconducting state and the pairing mechanism.
We report angle-resolved photoemission spectroscopy measurements of
superconducting (La,Pr,Sm)3Ni2O7 thin films by developing an ultra-high vacuum
cryogenic sample quenching and transfer technique. A superconducting gap of ~18
meV with coherence peaks is observed along the Brillouin zone diagonal. The
finite gap persists across the entire Brillouin zone, revealing the absence of
gap nodes. A kink is observed in the energy-momentum dispersion at ~70 meV below
Fermi level, indicating an electron-boson coupling. The simultaneous observation
of a nodeless superconducting gap and electron-boson coupling provides insight
into the pairing symmetry and gluing mechanism in RP bilayer nickelates.
DOI: 10.1126/science.adw8329