Kinematic spin-fluctuation mechanism of high-temperature superconductivity

Плакида, Н. М.; Oudovenko, V. S.

doi:10.1134/s1063776114080123

Cited by 14 publications

(17 citation statements)

References 31 publications

(66 reference statements)

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“…One of the possibilities to develop the theory in this direction is to use the atomic representation [140] and the diagram technique for the Hubbard operators [152,153]. The relevant models that can be used for the investigation of the Kohn-Luttinger renormalization are the generalized t − J − V model [154][155][156][157] and the t−J * −V model (which takes three-center interactions into account), whose important role in describing the superconducting state was studied in [158][159][160][161][162][163][164][165]. These models, which can be derived from the Shubin-Vonsovsky model in a certain range of parameters, effectively represent its low-energy versions.…”

Section: Superconductivity In the 2d T-j Modelmentioning

confidence: 99%

Anomalous superconductivity and superfluidity in repulsive fermion systems

2015

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We discuss the mechanisms of unconventional superconductivity and superfluidity in 3D and 2D fermionic systems with purely repulsive interaction at low densities. We construct phase diagrams of these systems and find the areas of the superconducting state in free space, as well as on the lattice in the framework of the Fermi-gas model with hard-core repulsion, the Hubbard model, the Shubin-Vonsovsky model, and the t − J model. We demonstrate that the critical superconducting temperature can be greatly increased in the spin-polarized case or in a two-band situation already at low densities. The proposed theory is based on the Kohn-Luttinger mechanism or its generalizations and explains or predicts anomalous p-, d-, and f -wave pairing in various materials, such as high-temperature superconductors, the idealized monolayer and bilayer of doped graphene, heavy-fermion systems, layered organic superconductors, superfluid 3 He, spin-polarized 3 He mixtures in 4 He, ultracold quantum gases in magnetic traps, and optical lattices.

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Section: Superconductivity In the 2d T-j Modelmentioning

confidence: 99%

Anomalous superconductivity and superfluidity in repulsive fermion systems

2015

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“…The factor of 2 can be generic to strongly correlated electron systems. In fact, similar features are recognized in slave-boson calculations [46], the Kadanoff-Baym method for Hubbard operators [68], the equation of motion method for the Green's functions in terms of the Hubbard operators [69], and the equations of motion for projected operators on the t-J model [70].…”

Section: Discussionmentioning

confidence: 67%

Electron self-energy from quantum charge fluctuations in the layered t−J model with long-range Coulomb interaction

2021

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Employing a large-N scheme of the layered t-J model with the long-range Coulomb interaction, which captures the fine details of the charge excitation spectra recently observed in cuprate superconductors, we explore the role of charge fluctuations on the electron self-energy. We fix the temperature at zero and focus on quantum charge fluctuations. We find a pronounced asymmetry of the imaginary part of the self-energy Im (k, ω) with respect to ω = 0, which is driven by strong electron correlation effects. The quasiparticle weight is reduced dramatically, which occurs almost isotropically along the Fermi surface. Concomitantly, an incoherent band and a sharp side band are generated and acquire sizable spectral weight. All these features are driven by the usual on-site charge fluctuations, which are realized in a rather high-energy region and yield plasmon excitations. On the other hand, the low-energy region with the scale of the superexchange interaction J is dominated by bond-charge fluctuations. Surprisingly, compared with the effect of on-site charge fluctuations, their effect on the electron self-energy is much weaker, even if the system approaches close to bond-charge instabilities. Furthermore, quantum charge dynamics does not produce a clear kink nor a pseudogap in the electron dispersion.

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“…This result is contrary to other results that suggest that superconductivity is killed by V already for values of the order of J (Refs. [23][24][25]).…”

Section: Resultsmentioning

confidence: 99%

Superconductivity with and without glue and the role of the double-occupancy forbidding constraint in the t-J-V model

Zinni,

Bejas,

Greco

2021

Preprint

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The occurrence of retarded (with glue) and unretarded (without glue) pairing is thoroughly discussed in cuprates. We analyze some aspects of this problem in the context of the t-J-V model in a large-N approximation. When 1/N renormalizations are neglected the mean-field result is recovered, where the unretarded d-wave superconducting pairing triggered by the spinexchange interaction J is obtained. However, the presence of a non-negligible nearest-neighbors Coulomb interaction V (q) kills superconductivity. If the non-double-occupancy constraint and its fluctuations are considered, the situation changes drastically. In this case, V (q) is screened making d-wave superconductivity very robust. In addition, we show that the early proposal for the presence of an unretarded pairing contribution triggered by the spin-exchange interaction J can be discussed in this context.

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Kinematic spin-fluctuation mechanism of high-temperature superconductivity

Cited by 14 publications

References 31 publications

Anomalous superconductivity and superfluidity in repulsive fermion systems

Anomalous superconductivity and superfluidity in repulsive fermion systems

Electron self-energy from quantum charge fluctuations in the layered t−J model with long-range Coulomb interaction

Superconductivity with and without glue and the role of the double-occupancy forbidding constraint in the t-J-V model

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