Characterization of the Edge States in Colloidal Bi<sub>2</sub>Se<sub>3</sub> Platelets.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38624179.
- Also identified by DOI 10.1021/acs.nanolett.3c04460 and PMC identifier 11066965.
- 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
The remarkable development of colloidal nanocrystals with controlled dimensions and surface chemistry has resulted in vast optoelectronic applications. But can they also form a platform for quantum materials, in which electronic coherence is key? Here, we use colloidal, two-dimensional Bi<sub>2</sub>Se<sub>3</sub> crystals, with precise and uniform thickness and finite lateral dimensions in the 100 nm range, to study the evolution of a topological insulator from three to two dimensions. For a thickness of 4-6 quintuple layers, scanning tunneling spectroscopy shows an 8 nm wide, nonscattering state encircling the platelet. We discuss the nature of this edge state with a low-energy continuum model and ab initio GW-Tight Binding theory. Our results also provide an indication of the maximum density of such states on a device.