title: Interfacial superconductivity in a bi-collinear antiferromagnetically ordered FeTe monolayer on a topological insulator.
abstract: The discovery of high-temperature superconductivity in Fe-based compounds triggered numerous investigations on the interplay between superconductivity and magnetism, and on the enhancement of transition temperatures through interface effects. It is widely believed that the emergence of optimal superconductivity is intimately linked to the suppression of long-range antiferromagnetic (AFM) order, although the exact microscopic picture remains elusive because of the lack of atomically resolved data. Here we present spin-polarized scanning tunnelling spectroscopy of ultrathin FeTe1-xSex(x=0, 0.5) films on bulk topological insulators. Surprisingly, we find an energy gap at the Fermi level, indicating superconducting correlations up to Tc∼6 K for one unit cell FeTe grown on Bi2Te3, in contrast to the non-superconducting bulk FeTe. The gap spatially coexists with bi-collinear AFM order. This finding opens perspectives for theoretical studies of competing orders in Fe-based superconductors and for experimental investigations of exotic phases in superconducting layers on topological insulators.
authors.affiliation: Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Manna
authors.affiliation: Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kamlapure
authors.affiliation: Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Cornils
authors.affiliation: Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Hänke
authors.affiliation: Department of Chemistry and iNANO, Center for Materials Crystallography, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
authors.forename: E M J
authors.initials: EM
authors.lastname: Hedegaard
authors.affiliation: Department of Chemistry and iNANO, Center for Materials Crystallography, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Bremholm
authors.affiliation: Department of Chemistry and iNANO, Center for Materials Crystallography, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
authors.forename: B B
authors.initials: BB
authors.lastname: Iversen
authors.affiliation: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Ph
authors.initials: P
authors.lastname: Hofmann
authors.affiliation: Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Wiebe
authors.affiliation: Department of Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Wiesendanger