title: Evidence for orbital order and its relation to superconductivity in FeSe0.4Te0.6.
abstract: The emergence of nematic electronic states accompanied by a structural phase transition is a recurring theme in many correlated electron materials, including the high-temperature copper oxide- and iron-based superconductors. We provide evidence for nematic electronic states in the iron-chalcogenide superconductor FeSe0.4Te0.6 from quasi-particle scattering detected in spectroscopic maps. The symmetry-breaking states persist above T c into the normal state. We interpret the scattering patterns by comparison with quasi-particle interference patterns obtained from a tight-binding model, accounting for orbital ordering. The relation to superconductivity and the influence on the coherence length are discussed.
authors.affiliation: Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
authors.forename: Udai R
authors.initials: UR
authors.lastname: Singh
authors.affiliation: Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
authors.forename: Seth C
authors.initials: SC
authors.lastname: White
authors.affiliation: Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schmaus
authors.affiliation: Center for Electronic Correlations and Magnetism, Experimental Physics V, University of Augsburg, D-86159 Augsburg, Germany. ; Institute of Applied Physics, Academy of Sciences of Moldova, MD 2028 Chisinau, Republic of Moldova.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Tsurkan
authors.affiliation: Center for Electronic Correlations and Magnetism, Experimental Physics V, University of Augsburg, D-86159 Augsburg, Germany.
authors.forename: Alois
authors.initials: A
authors.lastname: Loidl
authors.affiliation: Center for Electronic Correlations and Magnetism, Experimental Physics V, University of Augsburg, D-86159 Augsburg, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Deisenhofer
authors.affiliation: Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany. ; Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Wahl
keywords: Superconductivity; iron-based superconductors; nematicity; quasi-particle interference; scanning tunneling microscopy and spectroscopy; symmetry breaking