2015/03/31 by Grégoire Lhoutellier, Raymond Frésard, Andrzej M. Oleś · 1 citation
Materials Science · Physics and Astronomy · #Condensed matter physics #Coulomb #Electron #Exchange interaction #Fermi liquid theory #Ferromagnetism #Hubbard model #Instability #Iron-based superconductors research #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum mechanics #Superconductivity #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.91.224410
published as Physical Review B 91, 224410 (2015) · 12 pages, 10 figures
openalex publication_date 2015/06/08 · arxiv created 2015/06/11 · arxiv updated 2015/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the Landau parameters for the instabilities in spin and charge channels in the nondegenerate extended Hubbard model with intersite Coulomb and exchange interactions. To this aim we use the spin rotationally invariant slave boson approach and we determine the necessary inverse propagator matrix. The analytically derived spin Landau parameter F0a for the half filled band uncovers the intrinsic instability of the nondegenerate Hubbard model towards ferromagnetism---negative intersite exchange interaction triggers a ferromagnetic instability at half filling before the metal-insulator transition, indicated by the divergence of the magnetic susceptibility at F0a=\ensuremath-1. This result is general and the instability occurs in the strongly correlated metallic regime for any lattice, in three or two dimensions. Next as an illustrative example we present numerical results obtained for the cubic lattice with nearest neighbor exchange J and Coulomb V elements and arbitrary electron density. One finds that the range of small doping near half filling is the most unstable one towards spin polarization, but only in the case of ferromagnetic intersite exchange J<0. Charge Landau parameter F0s is lowered near half filling by increasing U when the intersite Coulomb interaction V is attractive, but in contrast to F0a at J<0 it requires an attraction beyond a critical value Vc to generate the divergence of the charge susceptibility at F0s=\ensuremath-1 in the metallic phase. This instability was found for a broad range of electronic filling away from half filling for moderate attraction.