title: Interrogating the superconductor Ca10(Pt4As8)(Fe2-xPtxAs2)5Layer-by-layer.
abstract: Ever since the discovery of high-Tcsuperconductivity in layered cuprates, the roles that individual layers play have been debated, due to difficulty in layer-by-layer characterization. While there is similar challenge in many Fe-based layered superconductors, the newly-discovered Ca10(Pt4As8)(Fe2As2)5provides opportunities to explore superconductivity layer by layer, because it contains both superconducting building blocks (Fe2As2layers) and intermediate Pt4As8layers. Cleaving a single crystal under ultra-high vacuum results in multiple terminations: an ordered Pt4As8layer, two reconstructed Ca layers on the top of a Pt4As8layer, and disordered Ca layer on the top of Fe2As2layer. The electronic properties of individual layers are studied using scanning tunneling microscopy/spectroscopy (STM/S), which reveals different spectra for each surface. Remarkably superconducting coherence peaks are seen only on the ordered Ca/Pt4As8layer. Our results indicate that an ordered structure with proper charge balance is required in order to preserve superconductivity.
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Jisun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Physics, The University of Texas, Austin, TX 78712, USA.
authors.forename: Hyoungdo
authors.initials: H
authors.lastname: Nam
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Guorong
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: A B
authors.initials: AB
authors.lastname: Karki
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA.|Brookhaven National Laboratory, Upton, NY 11973, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Brookhaven National Laboratory, Upton, NY 11973, USA.
authors.forename: Yimei
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Physics, The University of Texas, Austin, TX 78712, USA.
authors.forename: Chih-Kang
authors.initials: CK
authors.lastname: Shih
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Jiandi
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Rongying
authors.initials: R
authors.lastname: Jin
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: E W
authors.initials: EW
authors.lastname: Plummer