title: Local destruction of superconductivity by non-magnetic impurities in mesoscopic iron-based superconductors.
abstract: The determination of the pairing symmetry is one of the most crucial issues for the iron-based superconductors, for which various scenarios are discussed controversially. Non-magnetic impurity substitution is one of the most promising approaches to address the issue, because the pair-breaking mechanism from the non-magnetic impurities should be different for various models. Previous substitution experiments demonstrated that the non-magnetic zinc can suppress the superconductivity of various iron-based superconductors. Here we demonstrate the local destruction of superconductivity by non-magnetic zinc impurities in Ba0.5K0.5Fe2As2 by exploring phase-slip phenomena in a mesoscopic structure with 119 × 102 nm(2) cross-section. The impurities suppress superconductivity in a three-dimensional 'Swiss cheese'-like pattern with in-plane and out-of-plane characteristic lengths slightly below ∼1.34 nm. This causes the superconducting order parameter to vary along abundant narrow channels with effective cross-section of a few square nanometres. The local destruction of superconductivity can be related to Cooper pair breaking by non-magnetic impurities.
authors.affiliation: 1] INPAC-Institute for Nanoscale Physics and Chemistry, KU Leuven, Celestijnenlaan 200D, Leuven B-3001, Belgium [2] Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210093, China [3] National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: 1] Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210093, China [2] National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Min
authors.initials: M
authors.lastname: Ji
authors.affiliation: Physikalisches Institut-Experimentalphysik II and Center for Collective Quantum Phenomena in LISA+, Universität Tübingen, Auf der Morgenstelle 14, Tübingen D-72076, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Schwarz
authors.affiliation: Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, Antwerp B-2020, Belgium.
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Ke
authors.affiliation: Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, Antwerp B-2020, Belgium.
authors.forename: Gustaaf
authors.initials: G
authors.lastname: Van Tendeloo
authors.affiliation: 1] National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan [2] Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Division of Quantum and Physical Chemistry and INPAC-Institute for Nanoscale Physics and Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven B-3001, Belgium.
authors.forename: Paulo J
authors.initials: PJ
authors.lastname: Pereira
authors.affiliation: 1] Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210093, China [2] National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Ya
authors.initials: Y
authors.lastname: Huang
authors.affiliation: INPAC-Institute for Nanoscale Physics and Chemistry, KU Leuven, Celestijnenlaan 200D, Leuven B-3001, Belgium.
authors.forename: Gufei
authors.initials: G
authors.lastname: Zhang
authors.affiliation: 1] National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan [2] Graduate School of Chemical Science and Engineering, Hokkaido University, Hokkaido 060-0810, Japan.
authors.forename: Hai-Luke
authors.initials: HL
authors.lastname: Feng
authors.affiliation: 1] National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan [2] Graduate School of Chemical Science and Engineering, Hokkaido University, Hokkaido 060-0810, Japan.
authors.forename: Ya-Hua
authors.initials: YH
authors.lastname: Yuan
authors.affiliation: National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hatano
authors.affiliation: Physikalisches Institut-Experimentalphysik II and Center for Collective Quantum Phenomena in LISA+, Universität Tübingen, Auf der Morgenstelle 14, Tübingen D-72076, Germany.
authors.forename: Reinhold
authors.initials: R
authors.lastname: Kleiner
authors.affiliation: Physikalisches Institut-Experimentalphysik II and Center for Collective Quantum Phenomena in LISA+, Universität Tübingen, Auf der Morgenstelle 14, Tübingen D-72076, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Koelle
authors.affiliation: Division of Quantum and Physical Chemistry and INPAC-Institute for Nanoscale Physics and Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven B-3001, Belgium.
authors.forename: Liviu F
authors.initials: LF
authors.lastname: Chibotaru
authors.affiliation: 1] National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan [2] Graduate School of Chemical Science and Engineering, Hokkaido University, Hokkaido 060-0810, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yamaura
authors.affiliation: 1] Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210093, China [2] National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Hua-Bing
authors.initials: HB
authors.lastname: Wang
authors.affiliation: Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210093, China.
authors.forename: Pei-Heng
authors.initials: PH
authors.lastname: Wu
authors.affiliation: 1] Graduate School of Chemical Science and Engineering, Hokkaido University, Hokkaido 060-0810, Japan [2] WPI-MANA, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Takayama-Muromachi
authors.affiliation: INPAC-Institute for Nanoscale Physics and Chemistry, KU Leuven, Celestijnenlaan 200D, Leuven B-3001, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Vanacken
authors.affiliation: INPAC-Institute for Nanoscale Physics and Chemistry, KU Leuven, Celestijnenlaan 200D, Leuven B-3001, Belgium.
authors.forename: Victor V
authors.initials: VV
authors.lastname: Moshchalkov