Energy Spectrum and Electrical Conductivity of Systems with the Strong Electronic Correlations

Abstract

Theory of electroconductivity in crystals with strong electron correlations is developed. Different approaches for description of disordered-systems’ electroconductivity are considered. The method of two-particle Green’s function (electroconductivity) calculation for disordered crystals is developed. The processes of electron scattering on spin and density fluctuations, ion-core potentials and vibrations of a crystal lattice are taken into account. Calculations are based on a diagram technique for temperature Green’s functions. The cluster expansion for two-particle Green function is obtained. The coherent-potential approximation is chosen as a zeroth-order one-site approximation in above-mentioned cluster expansion. The energy spectrum of electrons, atomic and magnetic orderings, optical conductivity, temperature and concentration dependences of electroresistance and spin-dependent transport of Fe–Co alloy are investigated.

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