Charge Orderings and Phase Separations in the Atomic Limit of the Extended Hubbard Model with Intersite Density-Density Interactions

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

Abstracts

EN

A simple effective model of charge ordered insulators is studied. The tight binding Hamiltonian consists of the effective on-site interaction U and the intersite density-density interactions W_{ij} (both: nearest-neighbour and next-nearest neighbour). In the analysis of the phase diagrams we have adopted the variational approach, which treats the on-site interaction term exactly and the intersite interactions within the mean-field approximation. The phase separated states have not been taken into account in previous analyses. Our investigations of two cases of the on-site interaction: attraction (U/(- W_{Q}) = - 10) and repulsion (U/(- W_{Q}) = 1.1) show that, depending on the values of the next-nearest neighbour attraction, the system can exhibit not only homogeneous phases: charge ordered and nonordered, but also various phase separated states (charge ordered-nonordered, charge ordered-charge ordered).

Keywords

EN

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

Discipline

• 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: 2010
• Volume: 118
• Issue: 2
• Pages: 350-352

Dates

published

2010-08

Contributors

author

K. Kapcia

• Electron States of Solids Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland

author

W. Kłobus

• Electron States of Solids Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland

author

S. Robaszkiewicz

• Electron States of Solids Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland

References

• 1. R. Micnas, J. Ranninger, S. Robaszkiewicz, Rev. Mod. Phys. 62, 113 (1990)
• 2. T. Goto, B. Lüthi, Adv. Phys. 52, 67 (2003)
• 3. B. Schmidt, H. Aoki, T. Cichorek, J. Custers, P. Gegenwart, M. Kohgi, M. Lang, C. Langhammer, A. Ochiai, S. Paschen, F. Steglich, T. Suzuki, P. Thalmeier, B. Wand, A. Yaresko, Physica B 300, 121 (2001)
• 4. D. Jérome, Chem. Rev. 104, 5565 (2004)
• 5. H. Seo, C. Hotta, H. Fukuyama, Chem. Rev. 104, 5005 (2004)
• 6. K. Kapcia, M.Sc. Thesis, Adam Mickiewicz University, Poznań 2009
• 7. K. Kapcia, W. Kłobus, S. Robaszkiewicz, in preparation
• 8. R. Micnas, S. Robaszkiewicz, K.A. Chao, Phys. Rev. B 29, 2784 (1984)
• 9. S. Robaszkiewicz, Acta Phys. Pol. A 55, 453 (1979); Phys. Status Solidi (b) 70, K51 (1975)

Identifiers

DOI

10.12693/APhysPolA.118.350