The effects of the next-nearest-neighbour density-density interaction in the atomic limit of the extended Hubbard model

Abstract

We have studied the extended Hubbard model in the atomic limit. The Hamiltonian analyzed consists of the effective on-site interaction U and the intersite density-density interactions Wij (both: nearest-neighbour and next-nearest-neighbour). The model can be considered as a simple effective model of charge ordered insulators. The phase diagrams and thermodynamic properties of this system have been determined within the variational approach, which treats the on-site interaction term exactly and the intersite interactions within the mean-field approximation. Our investigation of the general case taking into account for the first time the effects of longer-ranged density-density interaction (repulsive and attractive) as well as possible phase separations shows that, depending on the values of the interaction parameters and the electron concentration, the system can exhibit not only several homogeneous charge ordered (CO) phases, but also various phase separated states (CO-CO and CO-nonordered). One finds that the model considered exhibits very interesting multicritical behaviours and features, including among others bicritical, tricritical, critical-end and isolated critical points.

12 pages, 7 figures; final version, pdf-ReVTeX; corrected typos in reference; submitted to Journal of Physics: Condensed Matter

References in corpus (8)

• Theoretical Aspects of Charge Ordering in Molecular Conductors
• Incommensurate magnetic order and phase separation in the two-dimensional Hubbard model with nearest and next-nearest neighbor hopping
• Phase diagram of the Ising square lattice with competing interactions
• One-dimensional extended Hubbard model in the atomic limit
• Charge orderings in the atomic limit of the extended Hubbard model
• Tricritical Behavior in Charge-Order System
• Extended Hubbard model in the presence of a magnetic field
• Different orderings in the narrow-band limit of the extended Hubbard model on the Bethe lattice

Cited by in corpus (11)

• Doping driven metal-insulator transitions and charge orderings in the extended Hubbard model
• 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
• Diversity of charge orderings in correlated systems
• Competition between antiferromagnetic and charge density wave fluctuations in the extended Hubbard model
• 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
• 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
• Particle-Hole Asymmetry and Pinball Liquid in a Triangular-Lattice Extended Hubbard Model within Mean-Field Approximation
• Understanding disorder-induced zero-bias anomalies in systems with short-range interactions: An atomic-limit perspective