Quantum waveguide theory of Andreev reflection in multiband superconductors: the case of Fe-pnictides

Abstract

The problem of Andreev reflection between a normal metal and a multiband superconductor is addressed. The appropriate matching conditions for the wave function at the interface are established on the basis of an extension of quantum waveguide theory to these systems. Interference effects between different bands of the superconductor manifest themselves in the conductance and the case of FeAs superconductors is specifically considered, in the framework of a recently proposed effective two-band model, in the sign-reversed s-wave pairing scenario. Resonant transmission through surface Andreev bound states is found as well as destructive interference effects that produce zeros in the conductance at normal incidence. Both these effects occur at nonzero bias voltage.

7 pages, 11 figures References updated; modifications in text style only; Accepted for publication in Physical Review B

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Cited by in corpus (16)

• Proximity and Josephson effects in microstructures based on multiband superconductors
• The Josephson current in Fe-based superconducting junctions: theory and experiment
• Evidence of a universal and isotropic 2Δ/kBTC ratio in 122-type iron pnictide superconductors over a wide doping range
• Surface Bound States in n-band Systems with Quasiclassical Approach
• Two-channel point-contact tunneling theory of superconductors
• Andreev bound states in iron pnictide superconductors
• Quantum Waveguide Theory of the Josephson effect in Multiband Superconductors
• Single vortex structure in two models of iron pnictide $s^{\pm }$ superconductivity
• Gap Anisotropy in Iron-Based Superconductors: A Point-Contact Andreev Reflection Study of BaFe${}_{2-x}$Ni${}_x$As${}_2$ Single Crystals
• Observation of the Non-linear Meissner Effect
• Evidence for Nodal superconductivity in Sr${}_2$ScFePO${}_3$
• Minimal model of point contact Andreev reflection spectroscopy of multiband superconductors
• Impurity Scattering Rate and Coherence factor in Vortex Core of Sign-reversing s-wave Superconductors
• Odd-frequency Pairing in the Edge States of Superconducting Pnictides in the Coexistence Phase with Antiferromagnetism
• Andreev spectroscopy of Majorana states in topological superconductors with multipocket Fermi surfaces
• Effect of hybridization symmetry on topological phases of odd-parity multiband superconductors