Interaction Effects in a 1D Flat Band at a Topological Crystalline Step Edge.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36972710.
- Also identified by DOI 10.1021/acs.nanolett.2c03794 and PMC identifier 10103314.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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<sub>1-<i>x</i></sub>Sn<sub><i>x</i></sub>Se 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.