Interplay between Charge and Magnetic Orderings in the Zero-Bandwidth Limit of the Extended Hubbard Model for Strong On-Site Repulsion

• Authors: K. Kapcia , W. Kłobus , S. Robaszkiewicz
• Languages of publication: EN

Abstracts

EN

A simple effective model of charge ordered and (or) magnetically ordered insulators is studied. The tight binding Hamiltonian analyzed consists of (i) the effective on-site interaction U, (ii) the intersite density-density interaction W and (iii) intersite magnetic exchange interaction J^{z} (or J^{xy}) between nearest-neighbors. The intersite interaction are treated within the mean-field approximation. One shows that the systems considered can exhibit very interesting multicritical behaviors, including among others bicritical, tricritical, tetracritical and critical end points. The analysis of the model has been performed for an arbitrary electron concentration as well as an arbitrary chemical potential in the limit of strong on-site repulsion (U → +∞). The phase diagrams obtained in such a case are shown to consist of at least 9 different states, including four homogeneous phases: nonordered (NO), ferromagnetic (F), charge ordered (CO), ferrimagnetic (intermediate, I) and five types of phase separation: NO-NO, F-NO, F-F, CO-F, CO-I.

Keywords

EN

71.10.Fd; 71.45.Lr; 75.30.Fv; 64.75.Gh; 71.10.Hf

Discipline

• 75.30.Fv: Spin-density waves
• 71.45.Lr: Charge-density-wave systems(see also 75.30.Fv Spin-density waves)
• 71.10.Fd: Lattice fermion models (Hubbard model, etc.)
• 71.10.Hf: Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems
• 64.75.Gh: Phase separation and segregation in model systems (hard spheres, Lennard-Jones, etc.)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2012
• Volume: 121
• Issue: 5-6
• Pages: 1032-1034

Dates

published

2012-05

Contributors

author

K. Kapcia

• Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland

author

W. Kłobus

• Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland

author

S. Robaszkiewicz

• Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland

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Identifiers

DOI

10.12693/APhysPolA.121.1032