Daily Overview: Today’s research highlight focuses on phonon-mode-selective tuning of magnetism and superconductivity in trilayer nickelates. By combining ab initio calculations with the functional renormalization group, the study identifies an out-of-plane oxygen breathing mode with pronounced electron-phonon coupling and constructs a symmetry-resolved, layer-dependent coupling form. The relative phase among the three layers induces distinct retarded electron interactions, which in turn mode-selectively enhance or suppress spin-density-wave order and s±-wave superconductivity. The core mechanism involves screening-mediated spin-phonon interactions acting across energy scales: electron-phonon coupling first modifies high-energy charge screening, then reshapes low-energy magnetic fluctuations, and ultimately affects pairing. This work also reports a negative isotope coefficient for the magnetic state, in qualitative agreement with experiments, providing a microscopic framework for understanding isotope effects in trilayer nickelates and interlayer-phonon tuning of electronic ordered states. arXiv submission processing window: 2026-09-16 00:00 to 2026-09-16 00:00 UTC.

1. Mode-selective phonon effects on magnetism and superconductivity in trilayer nickelates

Summary: This study employs ab initio and functional renormalization group calculations to investigate the effects of electron-phonon coupling on magnetism and superconductivity in trilayer nickelates. The authors identify a significant electron-phonon coupling in the out-of-plane oxygen breathing mode and construct a symmetry-resolved, layer-dependent coupling. The relative phase among the three layers generates different retarded electron interactions, thereby mode-selectively enhancing or suppressing spin density wave order and s±-wave superconductivity. The mechanism involves a screening-mediated spin-phonon interaction spanning multiple energy scales: electron-phonon coupling first alters high-energy charge screening, then reshapes low-energy magnetic fluctuations, and ultimately affects pairing. The selected mode yields a negative isotope coefficient for the magnetic state, qualitatively consistent with experiments. These results reveal how interlayer phonons regulate electronically driven ordered states and provide a microscopic framework for understanding isotope effects in trilayer nickelates.