One-Electron Excitations vs. Collective Excitations in the 1D Falicov-Kimball Model with Hund Coupling at Half Filling

• Authors: J. Wrzodak , R. Lemański
• Languages of publication: EN

Abstracts

EN

The Falicov-Kimball model enriched with Ising-type Hund coupling between spins of itinerant electrons and magnetic ions is studied exactly on finite 1D rings. At half filling (one electron per site) and for the density of magnetic ions equal to 1/2 it is shown that many-electron collective excitations coupled to spin reorientations of the magnetic ions have much lower energy than single electron excitations. This property is caused by energy gaps formed at the Fermi levels in one-electron energy spectra of all relevant magnetic configurations of the ions. Consequently, low temperature properties of the system are not driven by one-particle, elementary electron excitations but many-particle collective excitations, where both electrons and spins of magnetic ions are involved. In addition, it is shown that many-body excitation spectra derived both from spin fluctuations and from charge fluctuations have a regular structure.

Keywords

EN

71.10.Fd; 71.10.Li; 75.10.-b

Discipline

• 71.10.Li: Excited states and pairing interactions in model systems
• 71.10.Fd: Lattice fermion models (Hubbard model, etc.)
• 75.10.-b: General theory and models of magnetic ordering(see also 05.50.+q Lattice theory and statistics)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2010
• Volume: 118
• Issue: 2
• Pages: 366-368

Dates

published

2010-08

Contributors

author

J. Wrzodak

• Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-422 Wrocław, Poland

author

R. Lemański

• Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-422 Wrocław, Poland

References

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• 4. M. Maśka, K. Czajka, Phys. Rev. B 74, 035109 (2006)
• 5. M. Barma, V. Subrahmanyam, Phase Transit. B 16, 303 (1989)

Identifiers

DOI

10.12693/APhysPolA.118.366