https://doi.org/10.1007/s100510170347
Integrable correlated electron model with next-nearest-neighbour interactions
1
Max Planck Institut für Physik Komplexer Systeme,
Nöthnitzer Str. 38, 01187 Dresden, Germany
2
B.I. Verkin Institute for Low Temperature Physics and
Engineering of the Ukrainian National Academy of Sciences,
47, Lenin Avenue, Kharkov 61164, Ukraine
3
Universität Dortmund, Fachbereich Physik, Otto-Hahn-Str.
4, 44221 Dortmund, Germany
4
Institut für Theoretische Physik, Universität zu
Köln, Zülpicher Str. 77, 50937 Köln, Germany
Corresponding author: a zvyagin@mpipks-dresden.mpg.de
Received:
13
September
2000
Published online: 15 January 2001
The exactly solvable model of supersymmetric 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.
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.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001