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Information × Registration Number 0220U100699, 0118U100167 , R & D reports Title Effects of correlation and frustration in strongly correlated electron and magnetic systems popup.stage_title Head Matveev Oleh P., Кандидат фізико-математичних наук Registration Date 24-01-2020 Organization Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine popup.description2  As a result of the research, the effects of strong local and nonlocal correlations in systems described by quantum lattice models of different dimensions are investigated by calculating and analyzing of their static and dynamic characteristics. The low-temperature properties of the quantum Heisenberg antiferromagnetic model on lattices of different geometries and dimensions in the presence of frustration between bonds are investigated. A systematic theory for such systems in regime of strong magnetic fields and low temperatures is constructed. Using the concept of localized magnons and perturbation theory, an effective models for the description of frustrated quantum Heisenberg antiferromagnets were constructed. Results for the observed thermodynamic quantities, which are measured in real compounds are obtained. Phase diagrams of the frustrated quantum Heisenberg antiferromagnet were analyzed on two-layer lattices of different geometries in the ground state. An influence of the induced by correlated hopping localization of itinerant electrons on the electronic charge and heat transport is discussed for the lightly doped Mott insulator phase of the Falicov-Kimball model with correlated hopping . Due to the electron-hole asymmetry and anomalous features on the DOS and transport function induced by correlated hopping, the strong enhancement of the Seebeck coefficient is observed at low temperatures, when the flatted dependence is displays in a wide temperature range. Also we studied the reconstruction of the optical conductivity and x-ray photoemission spectra for a wide range of the correlated hopping parametrs. An expression to calculate the nonequilibrium x-ray photoelectron emission spectra(core-hole propagator) was obtained. Сalculations for the cases of metallic and Mott insulator phases, and also in the vicinity of the metal-insulator transition for the Falicov-Kimball model were performed. Product Description popup.authors Baliha Vasyl Ya. Dobushovskyi Danylo A. Krupnitska Olesia M. popup.nrat_date 2020-04-02 Close