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Integrable correlated electron model with next-nearest-neighbour interactions |
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| Authors: | A.A. Zvyagin A. Klümper J. Zittartz |
| Affiliation: | Max Planck Institut für Physik Komplexer Systeme, N?thnitzer Str. 38, 01187 Dresden, Germany, DE Universit?t Dortmund, Fachbereich Physik, Otto-Hahn-Str. 4, 44221 Dortmund, Germany, DE Institut für Theoretische Physik, Universit?t zu K?ln, Zülpicher Str. 77, 50937 K?ln, Germany, DE |
| Abstract: | The exactly solvable model of supersymmetric t - J chains (STJC) of correlated electrons with next-nearest-neighbour (NNN) interactions is proposed and studied. The model with interactions between nearest neighbours and NNN interactions in one chain can also be considered as a two-chain model with zigzag-like coupling between the chains. The NNN interaction (coupling between chains) causes the onset of additional Dirac seas for low-lying charge and/or spin excitations. These Dirac seas change the low-energy (conformal) behavior of the model. The filling of those seas depends on the values of the NNN coupling (interactions between chains), external magnetic field and applied voltage. We identify the new ground state phases which appear due to the NNN as incommensurate ones. The NNN coupling in the incommensurate phases induces spontaneous magnetization and/or spontaneous filling of the Dirac sea for charge excitations (“spontaneous charge ordering”). The onset of this order implies a first order quantum phase transition driven by the field with hysteresis phenomena. Received 13 September 2000 |
| Keywords: | PACS. 71.10.Hf Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems – 71.27.+a Strongly correlated electron systems heavy fermions – 71.10.Fd Lattice fermion models (Hubbard model, etc.) – 71.10.Pm Fermions in reduced dimensions (anyons, composite fermions, Luttinger liquid, etc.) |
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