Doping-driven evolution of pairing symmetry in pressurized La3Ni2O7
Abstract
We investigate the superconducting pairing symmetry and its doping evolution in pressurized La3Ni2O7. For the undoped compound, the most favorable pairing state is found to be s±-wave, characterized by sign reversal of the gap functions between the Fermi pockets. A detailed analysis of the pairing interactions reveals that this unconventional state originates from repulsive interactions mediated by the magnetic odd modes of the bilayer nickelate. Upon hole doping, the γ Fermi pocket expands, which amplifies the intrapocket repulsions on this pocket. These repulsions, driven by the magnetic even modes, gradually dominates the pairing interactions and ultimately drive a transition in pairing symmetry from s±-wave to dxy-wave in the heavily hole-doped regime. In stark contrast, the s±-wave pairing persists under electron doping, even deep into the heavily electron-doped regime where a Lifshitz transition occurs. This finding suggests that the γ Fermi pocket is not essential for the emergence of superconductivity in bilayer nickelates. In fact, the s±-wave pairing becomes more robust in the absence of the γ pocket, as spin fluctuations are strongly enhanced by the favorable nesting between the α and β pockets --- a condition guaranteed by Luttinger's theorem and the Fermi surface topology. We believe that exploring the doping evolution of superconducting pairing will open a new realm for testing the pairing mechanism in pressurized La3Ni2O7.
Related
- Probing the pairing symmetry of moiré graphene superconductors
- Pairing symmetry and superconductivity from long-range Coulomb interactions in the extended t-t'-t''-Jz model for cuprates
- Superconducting Pairing Symmetry on Geometric-Algebra Foundations via the Scalar-Projection Method
- NMR evidence of pairing fluctuations above T c and absence of spin magnetism in the time-reversal symmetry-breaking state of Ba 1 − x K x Fe 2 As 2
- Doping-driven Mott transition from steady-state density functional theory
BibTeX
@misc{zhang2026dopingdriven,
title = {{Doping-driven evolution of pairing symmetry in pressurized La$_3$Ni$_2$O$_7$}},
author = {Hai-Yang Zhang and Yu-Jie Bai and Fan-Jie Kong},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.29091},
eprint = {2608.29091},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.29091},
}
RIS
TY - UNPB
TI - Doping-driven evolution of pairing symmetry in pressurized La_3Ni_2O_7
AU - Hai-Yang Zhang
AU - Yu-Jie Bai
AU - Fan-Jie Kong
PY - 2026
DA - 2026/08/29
PB - arXiv
DO - 10.48550/arxiv.2608.29091
UR - https://arxiv.org/abs/2608.29091
AB - We investigate the superconducting pairing symmetry and its doping evolution in pressurized La_3Ni_2O_7. For the undoped compound, the most favorable pairing state is found to be s_±-wave, characterized by sign reversal of the gap functions between the Fermi pockets. A detailed analysis of the pairing interactions reveals that this unconventional state originates from repulsive interactions mediated by the magnetic odd modes of the bilayer nickelate. Upon hole doping, the γ Fermi pocket expands, which amplifies the intrapocket repulsions on this pocket. These repulsions, driven by the magnetic even modes, gradually dominates the pairing interactions and ultimately drive a transition in pairing symmetry from s_±-wave to d_xy-wave in the heavily hole-doped regime. In stark contrast, the s_±-wave pairing persists under electron doping, even deep into the heavily electron-doped regime where a Lifshitz transition occurs. This finding suggests that the γ Fermi pocket is not essential for the emergence of superconductivity in bilayer nickelates. In fact, the s_±-wave pairing becomes more robust in the absence of the γ pocket, as spin fluctuations are strongly enhanced by the favorable nesting between the α and β pockets --- a condition guaranteed by Luttinger's theorem and the Fermi surface topology. We believe that exploring the doping evolution of superconducting pairing will open a new realm for testing the pairing mechanism in pressurized La_3Ni_2O_7.
ER -