Bad Metal Behavior and Lifshitz Transition of a Nagaoka Ferromagnet
Abstract
Using an extension of the fermionic functional renormalization group for systems where strong correlations give rise to projected Hilbert spaces, we calculate the phase diagram and the electronic spectral function of the Hubbard model at infinite on-site repulsion. For a square lattice with nearest-neighbor hopping we find that the ground state evolves from a paramagnetic Fermi liquid at low densities via a state with antiferromagnetic stripe order at intermediate densities to an extended Nagaoka ferromagnet at high densities. The single-particle spectral function of the Nagaoka ferromagnet exhibits a flat but rather broad band characteristic for an incoherent non-Fermi liquid. We identify two distinct ferromagnetic regimes separated by a Lifshitz transition.
Fields of Study & Subjects
Magnetic properties of thin films
Physics of Superconductivity and Magnetism
Rare-earth and actinide compounds
Publication details
- Journal / source
- Physical Review Letters
- Publisher
- American Physical Society (APS)
- Volume
- 137
- Issue
- 9
- Pages
- 096506–096506
- Publication date
- 5 August 2026
- Language
- EN