Scanning Tunneling Microscopy and Spectroscopy of Surface Impurities in the Unconventional Superconductor FeSe<sub>1-x</sub>Te<sub>x</sub>
ORAL
Abstract
Bulk FeSe1-xTex hosts unconventional superconductivity and nematicity, and may have non-trivial topological surface states. Resonant states from impurities provide a powerful local probe of electronic structure, and can be used to search for possible Majorana zero modes (MZMs) and give important insight into electronic order. Here we study the impurity effect in FeSe1-xTex with low-temperature scanning tunneling microscopy and spectroscopy. We image Fe-site and Se/Te-site surface impurities, all of which create low-energy resonant states inside the superconducting gap. A detailed comparison of these in-gap impurity states can provide insight into the superconducting order parameter, and is necessary to further clarify whether these resonances are MZMs. We also track nematicity in this material using quasiparticle interference (QPI) obtained at energies larger than the superconducting gap.
*This work was supported by US Department of Energy, Scanned Probe Division under Award Number DE-SC0014335.
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Presenters
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Thomas Neulinger
- University of Illinois - Urbana Champaign
- Physics, Univeristy of Illinois at Urbana-Champaign