Effect of Spin Fluctuations on the Superconducting Phase of Hubbard Fermions in the t-t'-t"-J* Model


Тип публикации: статья из журнала

Год издания: 2008

Идентификатор DOI: 10.1134/S1063776108120091

Ключевые слова: Electric conductivity, Fermions, Integral equations, Spin dynamics, Spin fluctuations, Anomalous components, Critical temperatures, Electron concentrations, Hubbard, Hubbard operators, Joint effects, Large systems, Nonhomogeneous equations, One-loop approximations, Order parameters, Renormalization, Scattering process, Self energies, Spin-fluctuation, Strongly correlated electrons, Superconducting phase, System of integral equations, Superconductivity

Аннотация: The effect of spin-fluctuation scattering processes on the region of the superconducting phase in strongly correlated electrons (Hubbard fermions) is investigated by the diagram technique for Hubbard operators. Modified Gor'kov equations in the form of an infinitely large system of integral equations are derived taking into accountПоказать полностьюcontributions of anomalous components P-0 sigma,((sigma) over bar0) of strength operator P. It is shown that spin-fluctuation scattering processes in the one-loop approximation for the t-t'-t"-J* model taking into account long-range hoppings and three-center interactions are reflected by normal (P-0 sigma, (0 sigma)) and anomalous (P-0 sigma, ((sigma) over bar0)) components of the strength operator. Three-center interactions result in different renormalizations of the kernels of the integral equations for the superconducting d phase in the expressions for the self-energy and strength operators. In this approximation for the d-type symmetry of the order parameter for the superconducting phase, the system of integral equations is reduced to a system of nonhomogeneous equations for amplitudes. The resultant dependences of critical temperature on the electron concentrations show that joint effect of long-range hoppings, three-center interactions, and spin-fluctuation processes leads to strong renormalization of the superconducting phase region.

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Выпуск журнала: Vol. 107, Is. 6

Номера страниц: 996-1008

ISSN журнала: 10637761

Место издания: NEW YORK



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