Experimental investigation of the suppressed superconducting gap and double-resonance mode in Ba1 -xKxFe2As2
Abstract
B a1 -xKxF e2A s2 has an exotic physical property, i.e., the C2 spin-density-wave phase suddenly changes to the C4 magnetic phase, and superconductivity is suppressed within a narrow composition range around x =0.25 . We have investigated the doping dependence of the electronic structure of B a1 -xKxF e2A s2 using angle-resolved photoemission spectroscopy (ARPES), and we found an anomaly in the superconducting (SC) gap structure only for x =0.25 in both the hole and electron Fermi surfaces. We also propose that the mechanism of a newly observed double-resonance peak by inelastic neutron scattering is understandable because of the SC gap obtained by ARPES. Our discovery reveals the important relationship between the C4-magnetic phase and superconductivity, and it provides an opportunity to survey the underlying relationship between the SC gap and the resonance mode in the hole-doped iron-based superconductor.
- Publication:
-
Physical Review B
- Pub Date:
- December 2019
- DOI:
- 10.1103/PhysRevB.100.235135
- Bibcode:
- 2019PhRvB.100w5135I