Using \emph{ab initio} band structure and DFT+dynamical mean-field theory methods we examine the effects of electron-electron interactions on the electronic structure, magnetic state, and structural phase stability of the recently discovered double-layer perovskite superconductor La3Ni2O7 (LNO) under pressure. Our results show the emergence of a double spin-charge-density stripe state characterized by a wave vector q=(41,41) arrangement of the nominally high-spin NiA2+ and low-spin NiB3+ ions (diagonal hole stripes oriented at 45∘ to the Ni-O bond) which form zigzag ferromagnetic chains alternating in the ab plane. The phase transition is accompanied by cooperative breathing-mode distortions of the lattice structure and leads to a reconstruction of the low-energy electronic structure and magnetic properties of LNO. We obtain a narrow-gap correlated insulator with a band gap value of ∼0.2 eV characterized by strong localization of the Ni 3d states and significant spin-orbital polarizations of the charge deficient NiB3+ ions. Our results suggest the importance of double exchange to determine the magnetic properties of LNO, similarly to that in charge-ordered manganites. We propose that spin and charge stripe fluctuations play an important role to tune superconductivity in LNO under pressure.
@article{arxiv.2410.15298,
title = {Electronic correlations and spin-charge-density stripes in double-layer La$_3$Ni$_2$O$_7$},
author = {I. V. Leonov},
journal= {arXiv preprint arXiv:2410.15298},
year = {2026}
}