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Modified equation of motion approach for metallic ferromagnetic systems with the correlated hopping interaction
Author(s) -
Górski Grzegorz,
Mizia Jerzy,
Kucab Krzysztof
Publication year - 2016
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201552722
Subject(s) - ferromagnetism , coulomb , condensed matter physics , physics , asymmetry , diagonal , hubbard model , perturbation theory (quantum mechanics) , quantum monte carlo , quantum , monte carlo method , statistical physics , equations of motion , quantum mechanics , mathematics , statistics , geometry , superconductivity , electron
We consider the extended Hubbard model with included nearest neighbors off‐diagonal correlated hopping interaction. This model is analyzed using the modified equation of motion (EOM) approach with double‐time Green's functions. In modified EOM method we calculate the retarded Green's function of the impurity by differentiating Green's functions over both time variables. The proposed model is used to investigate possibility of ferromagnetism in the itinerant system. We calculate the Curie temperature for different carrier concentrations, state densities with different asymmetry, different values of the Coulomb interaction and correlated hopping interaction. Results of our relatively simple method are compared and agree with the results of previous Quantum Monte Carlo and Modified Perturbation Theory calculations. This legitimates further use of this model in different physical applications, e.g., quantum dots.