Model of Vortex States in Hole-Doped Iron-Pnictide Superconductors

Abstract

Based on a phenomenological model with competing spin-density-wave (SDW) and extended s-wave superconductivity, the vortex states in Ba(1-x)K(x)Fe2As2 are investigated by solving Bogoliubov-de Gennes equations. Our result for the optimally doped compound without induced SDW is in qualitative agreement with recent scanning tunneling microscopy experiment. We also propose that the main effect of the SDW on the vortex states is to reduce the intensity of the in-gap peak in the local density of states and transfer the spectral weight to form additional peaks outside the gap.

Theory of mixed-state effect on NMR relaxation measurements in iron pnictide superconductors

“…In the presence of an applied magnetic field, our calculations show that the spatial variation of the s ± order parameter is similar to that obtained in Ref. 15 (not shown here). Figure 1(a) shows the zero-energy (ZE) LDOS in real space and the position of the sites [V: (16,16), S: (32, 16), C: (32, 0)] where we calculate ρ i (ω) and T −1 1 (i).…”

“…15, we conclude that the existence of this peak is robust since the magnetic field is about B = 23 Tesla in Ref. 15. The robustness of the peak has also been verified by STM experiment conducted at magnetic fields of 4 and 9 Tesla.…”

“…By comparing with Ref. 15, we conclude that the existence of this peak is robust since the magnetic field is about B = 23 Tesla in Ref. 15.…”

“…The reason we adopt this model is its ability 12 to qualitatively account for the doping evolution of the FS as observed by ARPES 13 on the K-and Co-doped 122-family of the iron pnictides. More importantly, based on this model, the existence of the negative-energy (NE) ingap peak in the local density of states (LDOS) at the vortex core center observed by scanning tunneling spectroscopy (STM) 14 has been successfully explained, 15 all justifying the validity of this model. In the presence of a magnetic field B perpendicular to the plane, the hopping integral can be expressed as t …”

Robust s±-wave superconductivity against multi-impurity in iron-based superconductors

“…We use a two-orbital four-band phenomenological model [15,24,25,26,27,28,29,30] [31,32,33,34,35,36]. The obtained results are consistent with the ARPES [37], neutron scattering [38] experiments.…”