Dresden 2017 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 59: Superconductivity: Fe-based Superconductors - FeSe and others
TT 59.5: Talk
Thursday, March 23, 2017, 10:30–10:45, HSZ 103
Spatial variation of the two-fold anisotropic superconducting gap in a monolayer of FeSe0.5Te0.5 on a topological insulator — •Anand Kamlapure1, Sujit Manna1, Lasse Cornils1, Torben Hänke1, Martin Bremholm2, Philip Hofmann3, Jens Wiebe1, and Roland Wiesendanger1 — 1Department of Physics, University of Hamburg, Hamburg, Germany — 2Department of Chemistry and Center for Materials Crystallography, Aarhus University, Denmark — 3Department of Physics and Astronomy, and Interdisciplinary Nanoscience Center iNANO, Aarhus University, Denmark
We present a low temperature scanning tunneling spectroscopy (STS) study of the superconducting properties of monolayers of FeSe0.5Te0.5 grown on the 3D topological insulator Bi2Se1.2Te1.8. While the morphology and the overall transition temperature resemble those of similarly doped bulk crystals, the spectroscopic data shows a much larger spatial inhomogeneity in the superconducting energy gaps. Despite the gap inhomogeneity all the spectra can be described with a two-fold anisotropic s-wave gap function. The two-fold nature of the gap symmetry is evident from the Bogoliubov quasiparticle interference (QPI) pattern which shows distinct C2 symmetric scattering intensities. We argue that the gap inhomogeneity emerges as a result of intrinsic disorder in our system similar to disordered conventional superconductors. Our system thus provides an ideal platform to study unconventional superconductivity in Fe chalcogenides in a single layer and in close proximity to a topological insulator.