Andreev bound states in iron pnictide superconductors - Condensed Matter > Superconductivity

Abstract: Recently, Andreev bound states in iron pnictide have been proposed as anexperimental probe to detect the relative minus sign in the $s \pm$-wavepairing. While previous theoretical investigations demonstrated the feasibilityof the approach, the local density of states in the midgap regime is small,making the detection hard in experiments. We revisit this important problemfrom the Bogoliubov-de Gennes Hamiltonian on the square lattice withappropriate boundary conditions. Significant spectral weights in the midgapregime are spotted, leading to easy detection of the Andreev bound states inexperiments. Peaks in the momentum-resolved local density of states appear andlead to enhanced quasiparticle interferences at specific momenta. We analyzethe locations of these magic spots and propose they can be verified inexperiments by the Fourier-transformed scanning tunneling spectroscopy.

Author: Wen-Min Huang, Hsiu-Hau Lin

Source: https://arxiv.org/