Robust superconductivity across the antiferromagnetic Fermi surface reconstruction in Nd_1.85Ce_0.15CuO₄

The electron-doped cuprates are an important piece of the puzzle to understand high-transition-temperature cuprate superconductors, but progress remains challenging due to conflicting thermodynamic, spectroscopic, and phase-sensitive measurements on the nature of the superconducting state. Recent advances in sample preparation have elucidated the role of annealing as an independent tuning parameter, allowing the exploration of new phase space. Here we report angle-resolved photoemission spectroscopy data on Nd_1.85Ce_0.15CuO₄ samples annealed with conventional and protected methods, resulting in different antiferromagnetic (AF) correlations and Fermi surface (FS) topologies but retain the same superconducting temperature. Through resolving the elusive Bogoliubov quasiparticle peaks, we quantitatively identify strong-coupling superconducting gap (Δ_SC) maxima at the hot spots where the unreconstructed FS crosses the AF zone boundary. With varying spectral signatures across the AF-induced FS reconstruction, the differently annealed samples exhibit comparable Δ_SC magnitudes and profiles at off-nodal momenta, but show a dramatic gap-to-gapless transformation at the node. This result suggests the superconducting properties in the electron-doped cuprates are insensitive to remarkable changes of the nodal electronic structure near the Fermi energy. Our findings pave the way to reconciling previous measurements and provide important clues for understanding high temperature superconductivity.