Related papers: A phenomenological multiband Eliashberg model for …
We study the existence of intraband and interband pairing in the extended two band and three-band Hubbard model. It is shown that including interband pairing significantly increases the superconducting critical temperature in comparison…
Multiorbital models are important to both the correlation physics and topological behavior of quantum materials. LiFeAs is a prototype iron pnictide suitable for indepth investigation of this issue. Its electronic structure is strikingly…
To understand the amazing variety of the superconducting states of Fe-based superconductors, we analyze the multiorbital Hubbard models for LaFeAsO and LiFeAs going beyond the random-phase approximation (RPA), by calculating the vertex…
The vast majority of superconductors have more than one Fermi surface, on which the electrons pair below the critical temperature $T_C$, yet their superconducting behavior can be well described by a single-band Bardeen-Cooper-Schrieffer…
We present self-consistent calculations of the multi-gap structure measured in some Fe-based superconductors. These materials are known to have structural disorder in real space and a multi-gap structure due to the $3d$ Fe-orbitals…
We present simple qualitative estimates for the maximal superconducting transition temperature, which may be achieved due to electron - phonon coupling in Eliashberg-McMillan theory. It is shown that in the limit of very strong coupling the…
The isotope effects for Fe based superconductors are considered by including the phonon and magnetic fluctuations within the two band Eliashberg theory. We show that the recently observed inverse isotope effects of Fe, $\alpha_{Fe} \approx…
In this letter, we reported the results of NMR study on LiFeAs single crystals. We find a strong evidence of the low temperature spin fluctuations; by changing sample preparation conditions, the system can be tuned toward an…
Even- and odd-frequency superconductivity coexist due to broken time-reversal symmetry under magnetic field. In order to describe this mixing, we extend the linearized Eliashberg equation for the spin and charge fluctuation mechanism in…
The two gaps in a two-band clean s-wave superconductor are evaluated self-consistently within the quasiclassical Eilenberger weak-coupling formalism with two in-band and one inter-band pairing potentials. Superfluid density, free energy and…
We report fully momentum dependent, self-consistent calculations of the gap symmetry, Fermi surface (FS) anisotropy and Tc of superconducting (SC) LiFeAs using the experimental band structure and a realistic small-q electron phonon…
We investigate the superconducting mechanism and the transition temperature of heav y fermion superconductor UPd_2Al_3 on the basis of a single band two-dimensional Hubbard model on triangular lattice, whi ch represents the most heavy band…
In the usual Ginzburg-Landau theory the critical value of the ratio of two fundamental length scales in the thery $\kappa_c=1/\sqrt{2}$ separates regimes of type-I and type-II superconductivity. The latter regime possess thermodynamically…
The rich variety of iron-based superconductors and their complex electronic structure lead to a wide range of possibilities for gap symmetry and pairing components. Here we solve in the 2-Fe Brillouin zone the full frequency-dependent…
Using the strong coupling diagram technique for calculating the electron Green's function of the two-dimensional Hubbard model we have summed infinite sequences of ladder diagrams, which describe interactions of electrons with spin and…
The Eliashberg theory of superconductivity accounts for the fundamental physics of conventional electron-phonon superconductors, including the retardation of the interaction and the effect of the Coulomb pseudopotential, to predict the…
We investigated the characteristics of the spin fluctuations mediated superconductivity employing the Eliashberg formalism. The effective interaction between electrons was modeled in terms of the spin susceptibility measured by the…
We study the superconducting instability mediated by spin fluctuations in the Eliashberg theory for a minimal two-band model of iron-based superconductors. While antiferromagnetic spin fluctuations can drive superconductivity (SC) as is…
The infinite-dimensional Hubbard model is studied by means of a modified perturbation theory. The approach reduces to the iterative perturbation theory for weak coupling. It is exact in the atomic limit and correctly reproduces the…
We show that two-band superconductors harbor hidden criticality deep in the superconducting state, stemming from the critical temperature of the weaker band taken as an independent system. For sufficiently small interband coupling $\gamma$…