Fresnel single aperture diffraction (FSAD) is proposed as a phase-sensitive probe for pairing symmetry and Fermi surface of a superconductor. We consider electrons injected, through a small aperture, into a thin superconducting (SC) layer. It is shown that in case of SC gap symmetry Δ(-kx,k ?)=Δ(kx,k?) with kx and k ? respectively the normal and parallel components of the electron Fermi wave vector, the quasiparticle FSAD pattern developed at the image plane is zeroth-order minimum if kxx=nπ (n is an integer and x is SC layer thickness). In contrast, if Δ(-kx,k?)=- Δ(kx,k?), the corresponding FSAD pattern is zeroth-order maximum. Observable consequences are discussed for iron-based superconductors of complex multiband pairings.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2011 Apr 21|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics