Competition between s-wave order and d-wave order in holographic superconductors

Sign reversal of the order parameter in s - wave superconductors

We show that in a superconductor where two or more bands cross the Fermi level it is possible, in the framework of the conventional (s-wave) BCS theory, that the sign of the superconducting gap is different on the different sheets of the Fermi surface. At least one of two conditions has to be satisfied: (1) The interband pairing interaction is weaker than the Coulomb pseudopotential, while the ...

Induction of non-d-wave order-parameter components by currents in d-wave superconductors

It is shown, within the framework of the Ginzburg-Landau theory for a superconductor with dx22y2 symmetry, that the passing of a supercurrent through the sample results, in general, in the induction of order-parameter components of distinct symmetry. The induction of s-wave and dxy(x22y2)-wave components is considered in detail. It is shown that in both cases the order parameter remains gapless...

Electrodynamics of s-Wave Superconductors Using First-Order Formalism

In this paper we give a derivation of a system of equations which generalize the London brothers and Ginzburg–Landau systems of equations, to describe the electrodynamics of s-wave superconductors. First, we consider a relativistically covariant theory in terms of gauge four-vector electromagnetic potential and scalar complex field. We use the first-order formalism to obtain the supplemented Ma...

Mixing of the order parameters with dx2-y2- and dxy-wave symmetry in d-wave superconductors.

On Distinguishing d-wave from Highly Anisotropic s-wave Superconductors

Systematic impurity doping in the Cu-O plane of the hole-doped cuprate superconductors may allow one to decide between unconventional (”d-wave”) and anisotropic conventional (”s-wave”) states as possible candidates for the order parameter in these materials. We show that potential scattering of any strength always increases the gap minima of such s-wave states, leading to activated behavior in ...