Dresden 2017 – wissenschaftliches Programm
TT 53.12: Poster
Mittwoch, 22. März 2017, 15:00–19:00, P2-OG2
Spin resonance of Ba1−xKxFe2As2 studied by neutron scattering — •Chul-Ho Lee1, Kunihiro Kihou1, Jitae Park2, Kazumasa Horigane3, Florian Wasser4, Navid Qureshi5, Yvan Sidis6, Jun Akimitsu3, and Markus Braden4 — 1AIST, Japan — 2MLZ, Germany — 3Okayama Univ., Japan — 4Universitat zu Koln, Germany — 5ILL, France — 6LLB, France
The remarkable enhancement of magnetic neutron scattering signals appearing in a superconducting phase, so called spin resonance, is important to examin since it could include information of Cooper pairing. Here, we examined the spin fluctuation of hole-doped Ba1−xKxFe2As2 by inelastic neutron scattering to clarify the doping dependence of spin resonance. Neutron scattering experiments were conducted using the triple-axis spectrometer PUMA at FRM ll, Germany and 2T1 at LLB, France. We have found that the behavior of the spin resonance dramatically changes around x = 0.66 . Resonance peaks have been observed clearly below 2Δs in the optimum doping region, while they are absent in the overdoped region. Instead, there is a transfer of spectral weight from energies below 2Δs to higher energies, peaking at values of 3Δs for x = 0.84. These results indicate a reduced impact of magnetism on Cooper pair formation in the overdoped region.
 C. H. Lee et al., Sci. Rep. 6, 23424 (2016)