Stable and metastable phases in the atomic limit of the extended Hubbard model with intersite density-density interactions

Abstract

We have studied a simple effective model of charge ordered insulators. The tight binding Hamiltonian consists of the effective on-site interaction U and the intersite density-density interaction Wij (both: nearest-neighbor and next-nearest-neighbor). In the analysis of the phase diagrams and thermodynamic properties of this model we have adopted the variational approach, which treats the on-site interaction term exactly and the intersite interactions within the mean-field approximation. Our investigations of the general case (as a function of the electron concentration) have shown that the system exhibits various critical behaviors including among others bicritical, tricritical, critical-end and isolated critical points. In this report we concentrate on the metastable phases and transitions between them. One finds that the first- and second order transitions between metastable phases can exist in the system. These transitions occur in the neighborhood of first as well as second order transitions between stable phases. For the case of on-site attraction the regions of metastable homogeneous phases occurrence inside the ranges of phase separated states stability have been also determined.

3 pages, 3 figures, pdf-ReVTeX, presented at The European Conference PHYSICS OF MAGNETISM 2011, June 27 - July 1, 2011, Poznań, POLAND

Cited by in corpus (12)

• Metastability and phase separation in a simple model of a superconductor with extremely short coherence length
• The magnetic field induced phase separation in a model of a superconductor with local electron pairing
• Some properties of two dimensional extended repulsive Hubbard model with intersite magnetic interactions - a Monte Carlo study
• Superconductivity, metastability and magnetic field induced phase separation in the atomic limit of the Penson-Kolb-Hubbard model
• Interplay and competition between superconductivity and charge orderings in the zero-bandwidth limit of the extended Hubbard model with pair hopping and on-site attraction
• Exact solution of the 1D Hubbard model with NN and NNN interactions in the narrow-band limit
• Charge-Order on the Triangular Lattice: A Mean-Field Study for the Lattice $S=1/2$ Fermionic Gas
• Extended Falicov-Kimball model: Exact solution for finite temperatures
• Extended Falicov-Kimball model: exact solution for the ground state
• Some exact results for the zero-bandwidth extended Hubbard model with intersite charge and magnetic interactions
• Charge-order on the triangular lattice: Effects of next-nearest-neighbor attraction in finite temperatures
• Charge-Ordered States and the Phase Diagram of the Extended Hubbard Model on the Bethe lattice