On the Phase Diagram of the Zero-Bandwidth Extended Hubbard Model with Intersite Magnetic Interactions for Strong On-Site Repulsion Limit
S. Murawski, K. Kapcia, G. Pawłowski and S. Robaszkiewicz
Electron States of Solids Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
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In this report we have analyzed a simple effective model for a description of magnetically ordered insulators. The Hamiltonian considered consists of the effective on-site interaction (U) and the intersite Ising-like magnetic exchange interaction (J) between nearest neighbors. For the first time the phase diagrams of this model have been determined within Monte Carlo simulation on 2D-square lattice. They have been compared with results obtained within variational approach, which treats the on-site term exactly and the intersite interactions within mean-field approximation. We show within both approaches that, depending on the values of interaction parameters and the electron concentration, the system can exhibit not only homogeneous phases: (anti-)ferromagnetic (F) and nonordered (NO), but also phase separated states (PS: F-NO).
DOI: 10.12693/APhysPolA.121.1035
PACS numbers: 71.10.Fd, 75.30.Fv, 64.75.Gh, 71.10.Hf