2008/07/02 by Hong Ding, H. Ding, P. Richard +20 · 26 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1209/0295-5075/83/47001
published as Europhysics Letters 83, 47001 (2008). See http://www.iop.org/EJ/abstract/0295-5075/83/4/47001 · 4 figures
arxiv created 2008/07/02 · openalex publication_date 2008/07/14 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We have performed a high-resolution angle-resolved photoelectron spectroscopy study on the newly discovered superconductor Ba 0.6 K 0.4 Fe 2 As 2 ( T c =37 K). We have observed two superconducting gaps with different values: a large gap (Δ∼12 meV) on the two small hole-like and electron-like Fermi surface (FS) sheets, and a small gap (∼6 meV) on the large hole-like FS. Both gaps, closing simultaneously at the bulk transition temperature ( T c ), are nodeless and nearly isotropic around their respective FS sheets. The isotropic pairing interactions are strongly orbital dependent, as the ratio 2Δ/ k B T c switches from weak to strong coupling on different bands. The same and surprisingly large superconducting gap due to strong pairing on the two small FSs, which are connected by the (π, 0) spin-density-wave vector in the parent compound, strongly suggests that the pairing mechanism originates from the inter-band interactions between these two nested FS sheets.