Work

Magnetic crossover in the one-dimensional Hubbard model in the presence of a magnetic field

Year: 2001

Type: article

Abstract: The ground-state (GS) properties of the one-dimensional (1D) Hubbard model at half-filling are examined in the presence of a magnetic field using the generalized mean-field (GMF) approach, which includes the spin-density and the electron-hole correlations on an equal footing. The GMF formalism provides insight into both the metal-insulator transition and the transition from itinerant to localized magnetism with applied field. The GMF theory can differentiate the energy gap from the antiferromagnetic order parameter in the presence of a magnetic field. The numerical results for the GS energy, the magnetization, the spin susceptibility, and the number of doubly occupied sites are in good agreement with the exact results over a wide range of U / t and h / t . The calculated h - U phase diagram exhibits a magnetic crossover from itinerant electron-hole pairs to a Bose-Einstein condensate state of local pairs. The overall picture of the magnetic crossover in 1D is found to be similar for the simple case of constant density of states, putting the GMF approach on a firmer basis in two and three dimensions.

Source: Journal of Physics Condensed Matter

DOI: 10.1088/0953-8984/13/31/313

Authors: A N Kocharian, Nicholas Kioussis, S H Park

Institution: California State University, Northridge

Language: English

Topic: Physics of Superconductivity and Magnetism

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, Ralph M. Parsons Foundation, California State University, Northridge, Division of Materials Research

Awards: RUI: Hybridization - Induced Magnetism in Correlated Electron Systems, RUI: Theoretical Studies of Strongly Correlated Electron Systems