Evidence of electron interaction with an unidentified bosonic mode in superconductor CsCaFeAsF
arXiv:2408.00469 · doi:10.1038/s41467-024-50833-9
Abstract
The kink structure in band dispersion usually refers to a certain electron-boson interaction, which is crucial in understanding the pairing in unconventional superconductors. Here we report the evidence of the observation of a kink structure in Fe-based superconductor CsCaFeAsF using angle-resolved photoemission spectroscopy. The kink shows an orbital selective and momentum dependent behavior, which is located at 15 meV below Fermi level along the Gamma-M direction at the band with dxz orbital character and vanishes when approaching the Gamma-X direction, correlated with a slight decrease of the superconducting gap. Most importantly, this kink structure disappears when the superconducting gap closes, indicating that the corresponding bosonic mode (9 meV) is closely related to superconductivity. However, the origin of this mode remains unidentified, since it cannot be related to phonons or the spin resonance mode (15 meV) observed by inelastic neutron scattering. The behavior of this mode is rather unique and challenges our present understanding of the superconducting paring mechanism of the bilayer FeAs-based superconductors.
14 pages, 4 figures
References in corpus (26)
- Theory of magnetic excitations in iron-based layered superconductors
- Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2
- Spin Gap and Resonance at the Nesting Wavevector in Superconducting FeSe0.4Te0.6
- Self-Consistent Vertex Correction Analysis for Iron-Based Superconductors: Mechanism of Coulomb-Interaction-Driven Orbital Fluctuations
- Three-dimensional Resonance in superconducting BaFeNiAs
- Anomalously Strong Near-Neighbor Attraction in Doped 1D Cuprate Chains
- Momentum-dependence of Superconducting Gap, strong-coupling dispersion Kink, and tightly bound Cooper pairs in the high-Tc (Sr,Ba)1-x(K,Na)xFe2As2 superconductors
- Superconductivity in KCaFeAsF with Separate Double FeAs Layers
- Effects of magnetism and doping on the electron-phonon coupling in BaFeAs
- Origin of charge transfer and enhanced electron-phonon coupling in single unit-cell FeSe films on SrTiO3
- Ubiquitous strong electron phonon coupling at the interface of FeSe/SrTiO3
- Observation of an Orbital Selective Electron-Mode Coupling in Fe-Based High- Superconductors
- Evidence of a spin resonance mode in the iron-based superconductor BaKFeAs from scanning tunneling spectroscopy
- Neutron spin resonance in a quasi-two-dimensional iron-based superconductor
- Angle-resolved photoemission spectroscopy of electron-doped cuprate superconductors: Isotropic electron-phonon coupling
- Spin Resonance in the New-Structure-Type Iron-Based Superconductor CaKFe4As4
- Charge Density Wave order and electron-phonon coupling in ternary superconductor BiRhSe
- Ultrafast Optical Spectroscopy Evidence of Pseudogap and Electron-Phonon Coupling in an Iron-Based Superconductor KCaFeAsF
- Anisotropy of incommensurate magnetic excitations in slightly overdoped BaKFeAs probed by polarized inelastic neutron scattering experiments
- Band-selective clean- and dirty-limit superconductivity with nodeless gaps in the bilayer iron-based superconductor CsCaFeAsF
- Nodal multigap superconductivity in the anisotropic iron-based compound RbCa2Fe4As4F2
- Preferred Spin Excitations in the Bilayer Iron-Based Superconductor CaK(FeNi)As with Spin-Vortex Crystal Order
- Observation of a neutron spin resonance in the bilayered superconductor CsCa2Fe4As4F2
- Pseudogap and Strong Pairing Induced by Incipient and Shallow Bands in the Quasi-Two-Dimensional KCaFeAsF
- Spectroscopic studies of the superconducting gap in the 12442 family of iron-based compounds
- Superconductivity-induced transverse plasma mode and phonon anomaly in the -axis response of the bilayer compound RbCaFeAsF