Ground States of the Falicov-Kimball Model Extended by Nonlocal Coulomb Interactions

• Authors: H. Čenčariková , P. Farkašovský , M. Žonda
• Languages of publication: EN

Abstracts

EN

The small-cluster exact-diagonalizations are used to study the ground states of the Falicov-Kimball model extended by nonlocal Coulomb interactions (the nearest-neighbour interaction U_{nn} and the correlated hopping t'). It is shown that the ground-state phase diagrams found for the conventional Falicov-Kimball model are strongly changed when the nonlocal interactions are added. This is illustrated for two selected values of the on-site Coulomb interaction (U) that represent typical behaviours of the model in the intermediate and strong coupling limit. A number of remarkable results are found. (i) The phase separation takes place for a wide range of U_{nn} and t' in both interaction limits. (ii) New types of inhomogeneous charge ordering are observed for nonzero U_{nn} and t'. (iii) Depending on the values of U_{nn} and t', the model is able to describe both the continuous as well as discontinuous changes of the f-electron occupation number.

Keywords

EN

75.10.Lp; 71.27.+a; 71.28.+d

Discipline

• 71.27.+a: Strongly correlated electron systems; heavy fermions
• 75.10.Lp: Band and itinerant models
• 71.28.+d: Narrow-band systems; intermediate-valence solids(for magnetic aspects, see 75.20.Hr and 75.30.Mb in magnetic properties and materials)

• Journal: Acta Physica Polonica A
• Year: 2008
• Volume: 113
• Issue: 1
• Pages: 287-290

Dates

published

2008-01

received

2007-07-09

Contributors

author

H. Čenčariková

• Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 041 01 Košice, Slovakia

author

P. Farkašovský

• Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 041 01 Košice, Slovakia

author

M. Žonda

• Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 041 01 Košice, Slovakia

References

• 1. L.M. Falicov, J.C. Kimball, Phys. Rev. Lett. 22, 997 (1969)
• 2. J. Freericks, V. Zlatic, Rev. Mod. Phys. 75, 1333 (2003)
• 3. J. Wojtkiewicz, R. Lemanski, Phys. Rev. B 64, 233103 (2001);H.Čenčariková, P. Farkašovský, Int. J. Mod. Phys. B 18, 357 (2004)
• 4. Z. Gajek, R. Lemanski, J. Magn. Magn. Mater. 272, E691 (2004)
• 5. P. Farkašovský, Phys. Rev. B 20, 1507 (2095);Eur. Phys. J. B 20, 209 (2001)
• 6. J. Rohler, Handbook on the Physics and Chemistry of Rare Earths, North Holland, Elsevier, 1987, p. 51 0

Identifiers

DOI

10.12693/APhysPolA.113.287