Related papers: How interband pairing increases the superconductiv…
We investigate superconductivity in a two-dimensional material described by a two-band heavy-fermion model, where hybridization between a dispersive band and a flat band introduces a quasi-flat dispersion to the otherwise localized…
The strength of the electron-phonon coupling parameter and its evolution throughout a solid's phase diagram often determines phenomena such as superconductivity, charge- and spin-density waves. Its experimental determination relies on the…
When the electron-phonon coupling is quadratic in the phonon coordinates, electrons can pair to form bipolarons due to phonon zero-point fluctuations, a purely quantum effect. We study superconductivity originating from this pairing…
We suggest that the high-temperature superconductivity is attributed to the director-roles of van Hove singularity between electron-electron interaction and electron-phonon interaction. Difference between the critical temperature and…
Epitaxial thin films of the heavy fermion superconductor UNi2Al3 with Tc{max}=0.98K were investigated. The transition temperature Tc depends on the current direction which can be related to superconducting gaps opening at different…
A strategy to enhance d-wave superconducting correlations is proposed based on our numerical study for correlated electron models for high-Tc cuprates. We observe that the pairing is enhanced when the single-electron level around (pi,0) is…
The ferromagnetic (FM) transition temperature (Tc) of a two-band Double-Exchange (DE) model for colossal magnetoresistance (CMR) materials is studied using dynamical mean-field theory (DMFT), in wide ranges of coupling constants, hopping…
We deal with a model for high-temperature superconductivity which maintains that in cuprates spin-singlet bonds are formed between electrons running in the neighbouring layers of copper oxide found in lattice of these materials. This model…
Kogan et al. [Phys. Rev. B 80, 014507 (2009)] present a two-band model to investigate its effect on superconducting properties as, e.g., the superfluid density, the specific heat, the dependence of the superconducting transition temperature…
Coupling between electrons and phonons (lattice vibrations) drives the formation of the electron pairs responsible for conventional superconductivity. The lack of direct evidence for electron-phonon coupling in the electron dynamics of the…
Using the Eliashberg strong coupling theory with vertex correction, we calculate maps of transition temperatures (T$_{c}$) of electron-phonon superconductors in full parameter space. The maximums of transition temperatures for…
In this study, the pairing mechanism for layered HTS materials based on attraction between electrons from adjacent layers is proposed. Initially, each layer has expanded Fermi sphere owing to ridged geometry. When the two layers are close…
We show that a clean multiband superconductor may display one or several phase transitions with increasing temperature from or to frustrated configurations of the relative phases of the superconducting order parameters. These transitions…
The study of multi-band superconductivity is relevant for a variety of systems, from ultra cold atoms with population imbalance to particle physics, and condensed matter. As a consequence, this problem has been widely investigated bringing…
It was obtained the equation for the definition of upper critical field $% H_{c_2}$ in the system with two overlapping energetic bands on the Fermi surface, which is valid for the whole temperature interval $0 \leq T < T_c$. The analytic…
The title compound is investigated by specific heat measurements in the normal and superconducting state supplemented by upper critical field transport, susceptibility and magnetization measurements. From a detailed analysis including also…
A model for high temperature superconductors based on the idea of Cooper pairs comprised of electrons from different bands is studied. We propose that the two bands relevant for the cuprates are comprised of Cu dx2-y2, dz2, planar O psigma,…
In order to explore why the multi-layered cuprates have such high Tc's, we have examined various inter-layer processes. Since the inter-layer one-electron hopping has little effects on the band structure, we turn to the inter-layer pair…
We study a four-band model for the iron oxypnictides, in which the superconducting properties are assumed to be determined by the interband coupling between hole-like and electron-like Fermi sheets. We show that reasonable parameters can…
We investigate pairing fluctuation effects in a two band fermionic system, where a shallow band in the Bardeen--Cooper--Schrieffer--Bose--Einstein condensation (BCS-BEC) crossover regime is coupled with a weakly interacting deep band.…