Spin-density wave and superconductivity in LaNiO under ambient pressure
arXiv:2411.12349 · doi:10.1103/PhysRevB.111.144502
Abstract
We investigate the spin-density wave (SDW) behavior and the potential for superconductivity (SC) in LaNiO under ambient pressure using a multi-orbital random-phase approximation (RPA). Starting with a twelve-orbital tight-binding model derived from density functional theory (DFT) calculations, we explore the influence of Hubbard interactions on SDW formation. Our analysis reveals a stripe-like SDW characterized by an incommensurate wave vector, , suggesting a possible density wave instability in agreement with recent experiments. This configuration is driven by nesting of outer-layer Ni orbitals and exhibits interlayer antiferromagnetic ordering between the top and bottom NiO layers, with the middle layer serving as a node. We demonstrate that the Hund's coupling is the primary driver of the observed SDW. While superconductivity is absent in the undoped system under ambient pressure, it becomes attainable with appropriate hole doping (), resulting in a SC gap structure similar to the high-pressure phase. Our study identifies the specific conditions for realizing the ambient pressure stripe density wave: . Additionally, when doping leads to sufficient nesting at (0,0), the system's magnetic fluctuations transition into a stable Neel-type antiferromagnetic state, analogous to the high-pressure case.
6 pages, 7 figures