Anomalous Superconducting-Gap Structure of Slightly Overdoped Ba(FeCo)As
arXiv:1408.4260 · doi:10.7566/JPSJ.83.093703
Abstract
We observed the anisotropic superconducting-gap (SC-gap) structure of a slightly overdoped superconductor, Ba(FeCo)As (), using three-dimensional (3D) angle-resolved photoemission spectroscopy. Two hole Fermi surfaces (FSs) observed at the Brillouin zone center and an inner electron FS at the zone corner showed a nearly isotropic SC gap in 3D momentum space. However, the outer electron FS showed an anisotropic SC gap with nodes or gap minima around the M and A points. The different anisotropies obtained the SC gap between the outer and inner electron FSs cannot be expected from all theoretical predictions with spin fluctuation, orbital fluctuation, and both competition. Our results provide a new insight into the SC mechanisms of iron pnictide superconductors.
11 pages, 4 figures
References in corpus (10)
- Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsOF}
- Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
- Scanning Tunneling Spectroscopy and Vortex Imaging in the Iron-Pnictide Superconductor BaFeCoAs
- Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2
- Microwave Surface-Impedance Measurements of the Magnetic Penetration Depth in Single Crystal Ba1-xKxFe2As2 Superconductors: Evidence for a Disorder-Dependent Superfluid Density
- Electronic structure of heavily electron-doped BaFeCoAs studied by angle-resolved photoemission
- Possible three dimensional nodes in the superconducting gap of BaFe(AsP)
- Abrupt change in the energy gap of superconducting Ba1-xKxFe2As2 single crystals with hole doping
- Calorimetric Evidence for Nodes in the Overdoped Ba(FeCo)As
- Specific Heat To Hc2: Evidence for Nodes or Deep Minima in the Superconducting Gap of Under- and Overdoped Ba(Fe1-xCox)2As2