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Interaction Effects in a 1D Flat Band at a Topological Crystalline Step Edge.

ABSTRACT: Step edges of topological crystalline insulators can be viewed as predecessors of higher-order topology, as they embody one-dimensional edge channels embedded in an effective three-dimensional electronic vacuum emanating from the topological crystalline insulator. Using scanning tunneling microscopy and spectroscopy, we investigate the behavior of such edge channels in Pb_1-xSn_xSe under doping. Once the energy position of the step edge is brought close to the Fermi level, we observe the opening of a correlation gap. The experimental results are rationalized in terms of interaction effects which are enhanced since the electronic density is collapsed to a one-dimensional channel. This constitutes a unique system to study how topology and many-body electronic effects intertwine, which we model theoretically through a Hartree-Fock analysis.

SUBMITTER: Wagner G

PROVIDER: S-EPMC10103314 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature

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Interaction Effects in a 1D Flat Band at a Topological Crystalline Step Edge.

Wagner Glenn G Das Souvik S Jung Johannes J Odobesko Artem A Küster Felix F Keller Florian F Korczak Jedrzej J Szczerbakow Andrzej A Story Tomasz T Parkin Stuart S P SSP Thomale Ronny R Neupert Titus T Bode Matthias M Sessi Paolo P

Nano letters 20230327 7

Step edges of topological crystalline insulators can be viewed as predecessors of higher-order topology, as they embody one-dimensional edge channels embedded in an effective three-dimensional electronic vacuum emanating from the topological crystalline insulator. Using scanning tunneling microscopy and spectroscopy, we investigate the behavior of such edge channels in Pb1-xSnxSe under doping. Once the energy position of the step edge is brought close to the F ...[more]

PMID: 36972710

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