Neutron Spin Resonance in the 112-Type Iron-Based Superconductor

We use inelastic neutron scattering to study the low-energy spin excitations of the 112-type iron pnictide Ca_{0.82}La_{0.18}Fe_{0.96}Ni_{0.04}As_{2} with bulk superconductivity below T_{c}=22  K. A two-dimensional spin resonance mode is found around E=11  meV, where the resonance energy is almost t...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2018-03, Vol.120 (13), p.137001-137001, Article 137001
Main Authors: Xie, Tao, Gong, Dongliang, Ghosh, Haranath, Ghosh, Abyay, Soda, Minoru, Masuda, Takatsugu, Itoh, Shinichi, Bourdarot, Frédéric, Regnault, Louis-Pierre, Danilkin, Sergey, Li, Shiliang, Luo, Huiqian
Format: Article
Language:English
Subjects:
Arsenic
Condensed Matter
Cooper pairs
Dependence
Electrons
Energy distribution
Excitation
Group 5A compounds
Inelastic scattering
Iron
Neutron scattering
Neutrons
Physics
Resonance scattering
Spin resonance
Strongly Correlated Electrons
Superconductivity
Superconductors
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We use inelastic neutron scattering to study the low-energy spin excitations of the 112-type iron pnictide Ca_{0.82}La_{0.18}Fe_{0.96}Ni_{0.04}As_{2} with bulk superconductivity below T_{c}=22  K. A two-dimensional spin resonance mode is found around E=11  meV, where the resonance energy is almost temperature independent and linearly scales with T_{c} along with other iron-based superconductors. Polarized neutron analysis reveals the resonance is nearly isotropic in spin space without any L modulations. Because of the unique monoclinic structure with additional zigzag arsenic chains, the As 4p orbitals contribute to a three-dimensional hole pocket around the Γ point and an extra electron pocket at the X point. Our results suggest that the energy and momentum distribution of the spin resonance does not directly respond to the k_{z} dependence of the fermiology, and the spin resonance intrinsically is a spin-1 mode from singlet-triplet excitations of the Cooper pairs in the case of weak spin-orbital coupling.
ISSN:0031-9007
1079-7114
DOI:10.1103/PhysRevLett.120.137001