Ginzburg-Landau surface energy of multiband superconductors: Derivation and application to selected systems

Abstract

We determine the energy of an interface between a multiband superconducting and a normal half-space, in presence of an applied magnetic field, based on a multiband Ginzburg-Landau (GL) approach. We obtain that the multiband surface energy is fully determined by the critical temperature, electronic densities of states, and superconducting gap functions associated with the different band condensates. This furthermore yields an expression for the thermodynamic critical magnetic field, in presence of an arbitrary number of contributing bands. Subsequently, we investigate the sign of the surface energy as a function of material parameters, through numerical solution of the GL equations. Here, we consider two distinct cases: (i) standard multiband superconductors with attractive interactions, and (ii) a three-band superconductor with a chiral ground state with phase frustration, arising from repulsive interband interactions. Furthermore, we apply this approach to several prime examples of multiband superconductors, such as metallic hydrogen and MgB${}_2$, based on microscopic parameters obtained from first-principles calculations.

References in corpus (8)

• Type-1.5 Superconductors
• Evolution of multi-gap superconductivity in the atomically thin limit: Strain-enhanced three-gap superconductivity in monolayer MgB${}_2$
• Ginzburg-Landau theory for multiband superconductors: microscopic derivation
• Superconducting Properties of the $s^{\pm }$-wave state: Fe-based superconductors
• Conditions for non-monotonic vortex interaction in two-band superconductors
• Anisotropic type-I superconductivity and anomalous superfluid density in OsB 2
• Anomalous diamagnetic response in multi-band superconductors with time-reversal broken symmetry
• Phase solitons in a weakly coupled three-component superconductor