Related papers: Positive and inverse isotope effect on superconduc…
It is well known that phonons can overscreen the bare Coulomb electron-electron repulsion, turning it into the effective attraction that binds the Cooper pairs responsible for BCS superconductivity. Here, we use a simple lattice model to…
Eliashberg theory generalized for the account of the electron-hole nonequivalence and electron correlations in the vertex function is used. The phonon contribution to the nodal electron Green function in cuprates is viewed. At non- zero…
Various unconventional isotope effects have been reported in high-temperature superconducting copper oxides which are beyond the scheme of BCS theory. Their origin is investigated within polaron theory which leads to a renormalization of…
We investigate the effect of isotope substitution on the electron-phonon interaction in the multi-band superconductor MgB2 using tunable laser based Angle Resolved Photoemission Spectroscopy. The kink structure around 70 meV in the $\sigma$…
We consider two issues related to the condensation energy in superconductors described by the Eliashberg theory for various forms of the pairing interaction, associated either with phonon or electronic mechanisms of superconductivity.…
Oxygen-isotope effect has been investigated in a recently discovered superconductor Sr_{0.4}K_{0.6}BiO_{3}. This compound has a distorted perovskite structure and becomes superconducting at about 12 K. Upon replacing ^{16}O with ^{18}O by…
In this paper we calculate ab initially the phonon dispersion relationship of the superconductor LaFeAsO and investigate a main property in the superconductor, the oxygen isotope effect. Based on this phonon dispersion relationship, we find…
Neither BCS theory nor London theory contain any charge asymmetry. However it is an experimental fact that a rotating superconductor always exhibits a magnetic field parallel, never antiparallel, to its angular velocity. This and several…
The basic features of multi-band superconductivity and its implications are derived. In particular, it is shown that enhancements of the superconducting transition temperature take place due to interband interactions. In addition, isotope…
We show that the interplay between spin-orbit coupling (SOC) and the paramagnetic response of itinerant electrons in proximitized superconductor/paramagnet systems gives rise to the inverse spin galvanic effect, i.e. generation of magnetic…
To investigate the possibility whether electron-phonon coupling can enhance orbital fluctuations in iron-based superconductors, we develop an ab initio method to construct the effective low-energy models including the phonon-related terms.…
Palladium hydrides display the largest isotope effect anomaly known in literature. Replacement of hydrogen with the heavier isotopes leads to higher superconducting temperatures, a behavior inconsistent with harmonic theory. Solving the…
The properties of the d-wave superconducting state in the two-dimensional system have been studied. It has been assumed, that the pairing mechanism is based on the electron-phonon and the electron-electron-phonon interactions. The obtained…
We predict a strong enhancement of the critical temperature in a conventional Bardeen-Cooper-Schrieffer (BCS) superconductor in the presence of a bosonic condensate of exciton-polaritons. The effect depends strongly on the ratio of the…
We theoretically study the direct and inverse spin Hall effects in a superconductor-normal metal-superconductor junction induced by a spin-orbit interaction that is invariant under spatial inversion. We show that a supercurrent induces a…
We consider the effect of strong electron-electron attraction on superconductivity in the dilute system of the negative U-centers. They couple to the conducting electronic states and mediate attraction between electrons. We predict the…
We investigate the isotope effect on the London penetration depth of a superconductor which measures $n_S/m^*$, the ratio of superfluid density to effective mass. We use a simplified model of electrons weakly coupled to a single phonon…
In the present paper, the impact of small Fermi energy on the selected parameters of the superconducting state in Ba$_{1-x}$K$_{x}$BiO$_{3}$ (BKBO) is studied at $x \in (0.3, 0.4, 0.5)$. This is done by employing the adiabatic and…
It is assumed that in some sense the High-T$_c$ superconductivity is similar to the quantum chromodynamics (QCD). This means that the phonons in High-T$_c$ superconductor have the strong interaction between themselves like to gluons in the…
The effects of static electric fields on the superconducting state are studied within a relativistic extension of the BCS theory of superconductivity.