English

Enhanced $s^\pm$-wave superconductivity in electron-doped La$_3$Ni$_2$O$_7$

Superconductivity 2026-05-21 v2 Strongly Correlated Electrons

Abstract

In cuprates, electron doping yields a much lower superconducting TcT_c than hole doping. For recently discovered nickelate superconductors, the analogous doping strategies become more challenging. Consequently, while hole-doped Ruddlesden-Popper (RP) nickelates have been extensively studied, electron-doped RP nickelates remain rarely explored both experimentally and theoretically. Here we fill this gap by systematically investigating the two-orbital bilayer model for three representative systems: bulk La3_3Ni2_2O7_7 at ambient pressure and 15\,GPa, and a heterostructure La3_3Ni2_2O7_7:La3_3Al2_2O7_7 that provides a feasible experimental route to electron doping. Using first-principle calculations and large-scale dynamical cluster quantum Monte Carlo simulations, we find that electron doping generically enhances s±s^\pm-wave pairing superconductivity (SC) in all three cases, with the heterostructure showing the highest TcT_c in the underdoped regime. Furthermore, our results suggest an inter-orbital cooperative mechanism that the pairing on the dx2y2d_{x^2-y^2} orbital, induced by that on the dz2d_{z^2} orbital, plays a vital role in the SC. This work provides the theoretical prediction of enhanced SC in electron-doped RP nickelates and calls for future experimental verification.

Keywords

Cite

@article{arxiv.2605.17520,
  title  = {Enhanced $s^\pm$-wave superconductivity in electron-doped La$_3$Ni$_2$O$_7$},
  author = {Xun Liu and Chao Deng and Wenfeng Wu and Liang Si and Mi Jiang},
  journal= {arXiv preprint arXiv:2605.17520},
  year   = {2026}
}

Comments

7 Pages, 5 figures and supplementary material