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Название: Metal-Insulator Transition and Antiferromagnetism in the Generalized Hubbard Model: Treatment of Correlation Effects
Авторы: Igoshev, P. A.
Irkhin, V. Y.
Дата публикации: 2021
Издатель: American Physical Society
American Physical Society (APS)
Библиографическое описание: Igoshev P. A. Metal-Insulator Transition and Antiferromagnetism in the Generalized Hubbard Model: Treatment of Correlation Effects / P. A. Igoshev, V. Y. Irkhin // Physical Review B. — 2021. — Vol. 104. — Iss. 4. — 045109.
Аннотация: The ground state for the half-filled t-t′ Hubbard model is treated within the Hartree-Fock approximation and the slave-boson approach including correlations. The criterium for the metal-insulator transition in the Slater scenario is formulated using an analytical free-energy expansion in the next-nearest-neighbor transfer integral t′ and in direct antiferromagnetic gap Δ. The correlation effects are generally demonstrated to favor the first-order transition. For a square lattice with a strong van Hove singularity, accidental close degeneracy of AFM and paramagnetic phases is analytically found in a wide parameter region. As a result, there exists an interval of t′ values for which the metal-insulator transition is of the first order due to the existence of the van Hove singularity. This interval is very sensitive to model parameters (direct exchange integral) or external parameters. For the simple and body-centered cubic lattices, the transition from the insulator AFM state with increasing t′ occurs to the phase of an AFM metal and is a second-order transition, which is followed by a transition to a PM metal. These results are quantitatively modified when taking into account the intersite Heisenberg interaction, which can induce first-order transitions. A comparison with the Monte Carlo results is performed. © 2021 American Physical Society.
Ключевые слова: ANTIFERROMAGNETISM
CORRELATION DETECTORS
FREE ENERGY
GROUND STATE
HARTREE APPROXIMATION
HUBBARD MODEL
METAL INSULATOR BOUNDARIES
METALS
SEMICONDUCTOR INSULATOR BOUNDARIES
BODY CENTERED CUBIC LATTICES
FIRST ORDER TRANSITIONS
FREE-ENERGY EXPANSION
HEISENBERG INTERACTION
MONTE CARLO RESULTS
PARAMAGNETIC PHASIS
SECOND ORDER TRANSITION
VAN HOVE SINGULARITIES
METAL INSULATOR TRANSITION
URI: http://elar.urfu.ru/handle/10995/111437
Условия доступа: info:eu-repo/semantics/openAccess
Идентификатор SCOPUS: 85109910169
Идентификатор PURE: 22835681
ISSN: 2469-9950
Сведения о поддержке: The authors are grateful to M. I. Katsnelson, M. A. Timirgazin, Yu. N. Skryabin, and A.O. Anokhin for fruitful discussions. This work was performed under the State assignment of the Ministry of Education of the Russian Federation (project “Quantum” No. AAAA-A18-118020190095-4).
Располагается в коллекциях:Научные публикации, проиндексированные в SCOPUS и WoS CC

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