Related papers: Isotope effects in multiband superconductors
Looking for superconductors with higher transition temperature requires a guiding principle. In conventional superconductors, electrons pair up into Cooper pairs via the retarded attraction mediated by electron-phonon coupling.…
We have investigated the effect of unconventional pairing mechanism in MgB2 using a two-band model within the framework of Bogoliubov-Valatin formalism. The approach incorporates the intra- band s-wave interaction in the s- and p-bands, as…
We analyze the paradigmatic competition between intra-band and cross-band Cooper-pair formation in two-band superconductors, neglected in most works to date. We derive the phase-sensitive gap equations and describe the crossover between the…
The interlayer pair tunneling model of Anderson et al. is generalized to include the strong coupling effects associated with in-plane interactions. The equations for the superconducting transition temperature T_{c} are solved numerically…
Developing a theory of high-temperature superconductivity in copper oxides is one of the outstanding problems in physics. Twenty-five years after its discovery, no consensus on the microscopic theory has been reached despite tremendous…
The temperature dependencies of the coupled superconducting gaps, observed in Fe-As based superconducting compounds is calculated and a universal temperature scaling observed which is only present if the coupled order parameters both have…
Nonmagnetic impurity scattering is known to shift up the Ginzburg-Landau parameter $\kappa$ of a superconductor. In this case, when the system is initially in type I, it can change its magnetic response, crossing the intertype domain with…
We show that various factors can lead to an isotopic dependence of the penetration depth $\delta$. Non-adiabaticity (Jahn-Teller crossing) leads to the isotope effect of the charge carrier concentration $n$ and, consequently, of $\delta$ in…
The strong coupling Eliashberg theory plus vertex correction is used to calculate maps of transition temperature (Tc) in parameter-space characterizing superconductivity. Based on these Tc maps, crossover behaviors are found when…
Anisotropic electron-phonon interaction is shown to lead to the anisotropic polaron effect. The resulting anisotropy of the polaron band is an exponential function of the electron-phonon coupling and might be as big as $10^3$. This also…
Strong electron-phonon interactions in cuprates and other high-temperature superconductors have gathered support over the last decade in a large number of experiments. Here I briefly introduce the Froehlich-Coulomb multi-polaron model of…
There is compelling evidence for a strong electron-phonon interaction (EPI) in cuprate superconductors from the isotope effects on the supercarrier mass, high resolution angle resolved photoemission spectroscopies (ARPES), a number of…
Developing a theory of high-temperature superconductivity in copper oxides is one of the outstanding problems in physics. It is a challenge that has defeated theoretical physicists for more than twenty years. Attempts to understand this…
The weak-coupling quantum phase diagrams of the one-dimensional (1D) Holstein-Hubbard and Peierls-Hubbard models are computed near half-filling, using a multi-step renormalization group technique. If strong enough, the electron-phonon…
The theory of thermodynamic properties of two-band superconductor with reduced density charge carriers is developed on the base of phonon superconducting mechanism with strong electron-phonon interaction. This theory is adapted to describe…
A simple two-band model with interband scattering of intraband pairs is applied to MgB$_2$ superconductivity. An adjustable parameters set is chosen. The calculated $T_c$ vs doping, isotope exponent and the heat capacity jump are in…
We study two aspects of the superconductivity in a cuprate model system, its doping dependence and the influence of competing pairing mediators. We first include electron-phonon interactions beyond Migdal's approximation and solve…
Isotope effects on heat conduction and convection have been known for decades. However, whether thermal radiation can be isotopically engineered remains an open question. Here, we predict over 3-orders-of-magnitude variation of radiative…
In a recent paper Yanagisawa et al. [1] claim from a theoretical analysis of a multi-channel multi-band superconductor model that an inverse isotope exponent on the superconducting transition temperature Tc can be realized in iron-based…
The recent observation of an inflection point in the temperature dependence of the in-plane magnetic field dependence (lambda_ab) is investigated within a two-band model with coupled order parameters of different symmetries. While the…