title: Model for determining the pairing symmetry and relative sign of the energy gap of iron-arsenide superconductors using tunneling spectroscopy.
abstract: We demonstrate that tunneling into multiband iron-arsenide superconductors through a wide junction in the transparent limit can provide unambiguous signatures for the symmetry and relative sign nu of the pairing gaps on the Gamma and M Fermi pockets. For antiphase s-wave pairing, Andreev reflections can be thoroughly suppressed by interband destructive interference. This also occurs for tunneling along the antinodal (nodal) direction of antiphase (in-phase) d-wave gaps with distinctive line shapes in the spectra as compared to the s-wave case. If nu is reversed, Andreev reflections survive but are subject to interband decoherence due to quasiparticles.
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Da
authors.initials: D
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wan
authors.forename: Qiang-Hua
authors.initials: QH
authors.lastname: Wang