Probing interaction effects at a topological crystalline step edge by Scanning tunneling Microscopy and Scanning tunneling Spectroscopy

ORAL

Abstract

Topological Crystalline Insulators (TCIs) are the class of materials in which the topological nature of electronic structure arises from crystal symmetries. With the realization of a TCI phase in Pb1-xSnxSe it was perceived that the step edges in TCIs can be viewed as predecessors of higher-order topology, as they embody one-dimensional (1D) edge channels embedded in an effective three-dimensional electronic vacuum emanating from the TCI. Here we use scanning tunneling microscopy and spectroscopy to investigate the behavior of these 1D step-edge channels under the influence of doping. By doping distinct 3d adatoms in Pb1-xSnxSe we observed that once the energy position of the 1D step-edge mode is brought close to the fermi level, a new correlation gap starts to open. Our experimental findings are rationalized in terms of enhanced interaction effects since the electron density of states is collapsed to a 1D channel. This enables us to realize a unique system to study how topology and many-body electronic effects intertwine.

*We acknowledge support from:1. NCCR MARVEL funding from the SWISS National Foundation. 2. Foundation for Polish Science through IRA Programme co-financed by EU within Smart Growth Operational Programme for supporting crystal growth and characterization.3. Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) through QUAST FOR 5249-449872909.4. Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) through Project-ID 258499086-SFB 1170 and the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter – ct.qmat

–

Publication: Interaction effects in a 1D flat band at a topological crystalline step edge
G. Wagner et al.(arXiv:2209.06837)

Presenters

  • Souvik Das

    • Max Planck Institute of Microstructure Physics

Authors

  • Souvik Das

    • Max Planck Institute of Microstructure Physics

  • Glenn Wagner

    • Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland

  • Johannes Jung

    • Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

  • Artem Odobesko

    • Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

  • Felix Küster

    • Max Planck Institute of Microstructure Physics, Halle 06120, Germany

  • Florian Keller

    • Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

  • Jedrzej Korczak

    • Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland; International Research Centre MagTop, Institute of Physics

  • Andrzej Szczerbakow

    • Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland

  • Tomasz Story

    • Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland; International Research Centre MagTop, Institute of Physics

  • Stuart Parkin

    • Max Planck Inst Microstructure
    • Max Planck Institute of Microstructure Physics
    • Max Planck Institute of Microstructure Physics, Halle 06120, Germany

  • Ronny Thomale

    • Julius-Maximilians University of Wuerzburg
    • Julius-Maximilians University of Wuerzbu
    • Institut für Theoretische Physik und Astrophysik Universität Würzburg, 97074 Würzburg, Germany
    • University of Wuerzburg

  • Titus Neupert

    • Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland

  • Matthias Bode

    • Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

  • Paolo Sessi

    • Max Planck Institute of Microstructure Physics, Halle 06120, Germany