1304.6424 (S. Mukherjee et al.)

Low-energy bound states at interfaces between superconducting and block
antiferromagnet regions in KxFe{2-y}Se2    [PDF]

S. Mukherjee, M. N. Gastiasoro, P. J. Hirschfeld, B. M. Andersen

The high-Tc alkali doped iron selenide superconductors KxFe{2-y}Se2 have been recently shown to be intrinsically phase separated into Fe vacancy ordered block antiferromagnetic regions and superconducting regions at low temperatures. In this work, we use a microscopic five orbital Hubbard model to obtain the electronic low-energy states near the interfaces between block antiferromagnets and superconductors. It is found that abundant low-energy in-gap bound states exist near such interfaces irrespective of whether the superconductor has d- or s-wave pairing symmetry. By contrast, it is shown how nonmagnetic scattering planes can provide a natural means to distinguish between these two leading pairing instabilities of the KxFe{2-y}Se2 materials.

View original: http://arxiv.org/abs/1304.6424