Odd-frequency Pairing in the Edge States of Superconducting Pnictides in the Coexistence Phase with Antiferromagnetism

Abstract

In several members of the pnictide materials, spin density wave order coexists with superconductivity over a range of dopings and temperature. In this paper we show that odd-frequency superconductivity emerges on the edges of pnictides in such a coexistence phase. In particular, the breaking of spin-rotation symmetry by SDW and translation symmetry by the edge can lead to the development of odd-frequency spin-triplet Cooper pairing on edges of superconducting pnictide samples. In this case, the odd-frequency pairing has even parity components, which are immune to disorder. Our results show that pnictides are a natural platform to realize odd frequency superconductivity, which is a new quantum phase and has been mainly searched for in heterostructures of magnetic and superconducting materials. The emergence of odd-frequency pairing on the edges and in the defects can be potentially detected in magnetic response measurements.