Electronic structure, quasiparticle renormalizations, and magnetic correlations in the alternating single-layer bilayer nickelate
Phys. Rev. B 114, 285113 – Published 10 November, 2026
DOI: https://doi.org/10.1103/4dmx-knsn
Abstract
Using the dynamical mean-field theory () method, we study the normal-state electronic structure, orbital-dependent quasiparticle renormalizations, Fermi surface, and magnetic correlations in the recently discovered alternating single-layer bilayer hybrid Ruddlesden–Popper nickelate superconductor (1212-LNO). Our results for the electronic states exhibit qualitative differences for the structurally distinct single-layer and bilayer Ni ions, implying the importance of confinement and orbital-dependent correlations. The partially occupied Ni electronic states originating from the bilayer Ni ions form strongly renormalized quasiparticle bands with a large enhancement factor and 4.2 for the Ni and orbitals, respectively, implying the proximity of the Ni states to orbital-dependent localization. Moreover, the states of the single-layer Ni ions exhibit an orbital-selective Mott insulating state, with a narrow energy gap for the Ni states and metallic, strongly incoherent (non-Fermi-liquid) Ni ones. Our analysis of magnetic correlations suggests the formation of intertwined spin and charge density wave stripes in the bilayer slab, in close similarity to the double-layer material. We identify two major instabilities: a leading one associated with a propagating wave vector (associated, e.g., with an “up-down-0” spin pattern or “” charge-density wave with Ni ions bonded in an interlayer spin polaron), competing with the bicollinear (“up-up-down-down”) stripe state. In contrast, the single-layer Ni electrons exhibit an instability toward the Néel-type magnetic state. Under pressure, 1212-LNO undergoes an orbital-selective Mott insulator-to-metal phase transition, associated with metallization of the single-layer Ni states. As a result, the single-layer Ni bands exhibit non-Fermi-liquid (bad metal) behavior with strongly incoherent spectral weights near the Fermi level. We note that correlation effects result in a remarkable reconstruction of the symmetry and strength of magnetic correlations as compared to those obtained within DFT. In fact, we observe a crossover from single-layer (as obtained within DFT) to double-layer-dominated magnetic correlations.