Related papers: Isotope effects in multiband superconductors
In cuprate superconductors, a pronounced maximum of superconducting Tc is observed in compounds that have an in-plane Cu-O distance close to ~1.92 Angstroms. On the other hand, direct measurements of the electron-phonon coupling lambda as a…
The frequency structure of the superconducting correlations in cuprates gives insights on the pairing mechanism. Here we present an exhaustive study of this problem in the two-dimensional Hubbard model with cellular dynamical mean-field…
Despite being of fundamental importance and potential interest for topological quantum computing, spin-triplet superconductors remain rare in solid state materials after decades of research. In this work, we present a general mechanism for…
Within the two-band model of superconductivity, we study the dependence of the critical temperature Tc and of the isotope exponent alpha in the proximity to an electronic topological transition (ETT). The ETT is associated with a 3D-2D…
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…
Inspired by the recent experiments in monolayer iron-based superconductors, we theoretically investigate properties of a two-dimensional multiband superconductor, focusing on two aspects. First, for vortex bound states, the spatial…
Despite the intensive efforts for determining the mechanism that causes high-temperature superconductivity in copper oxide materials, no consensus on the pairing mechanism has been reached. Recent advances in high resolution angle-resolved…
We analyze the qualitative features in the transition spectra of a model superconductor with multiple energy gaps, using a simple extension of the Mattis-Bardeen expression for probes with case I and case II coherence factors. At…
The BCS picture of superconductivity describes pairing between electrons originating from a single band. A generalization of this picture occurs in multi-band superconductors, where electrons from two or more bands contribute to…
We study Cooper-pair phase fluctuations in cuprate superconductors for a spin fluctuation pairing interaction. Using an electronic theory we calculate in particular for the underdoped cuprate superconductors the superfluid density $n_s(T)$,…
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,…
We investigate a model for the CuO_2 plane of high-T_c superconductors where the charge carriers are coupled to A_{1g} and B_{1g} symmetric out-of plane vibrations of the oxygen atoms in the presence of local Hubbard correlations. The…
We suggest that the high temperature superconductivity in cuprate compounds may emerge due to interaction between copper-oxygen layers mediated by in-plane plasmons. The strength of the interaction is determined by the c-axis geometry and…
In conventional superconductors, phonons glue two electrons with opposite spins to form Cooper pairs and condensation of these pairs leads to the superconductivity. Identifying the underlying mechanism of the high temperature…
We introduce a multi-band BCS free energy functional and prove that for a multi-band superconductor the effect of inter-band coupling can only increase the critical temperature, irrespective of its attractive or repulsive nature and its…
The isotope effect in the superconducting transition temperature is anomalous if the isotope coefficient $\alpha<0$ or $\alpha>1/2$. In this work, we show that such anomalous behaviors can naturally arise within the…
We demonstrate that most features ascribed to strong correlation effects in various spectroscopies of the cuprates are captured by a calculation of the self-energy incorporating effects of spin and charge fluctuations. The self energy is…
The high-transition-temperature (high-Tc) superconductivity discovered recently in iron pnictides is analyzed within a perturbation theory. Specifically, the probable pairing symmetry, the doping dependence of the transition temperature and…
In conventional metals, electron-phonon coupling, or the phonon-mediated interaction between electrons, has long been known to be the pairing interaction responsible for the superconductivity. The strength of this interaction essentially…
Recent experiments on certain Fe-based superconductors have hinted at a role for paired electrons in "incipient" bands that are close to, but do not cross the Fermi level. Related theoretical works disagree on whether or not strong-coupling…