Phonons as a platform for non-Abelian braiding and its manifestation in layered silicates
2022 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 13, no 1, article id 423Article in journal (Refereed) Published
Abstract [en]
Multi-gap topology is a new avenue in topological phases of matter but it remains difficult to verify in real materials. Here, the authors predict multi-gap topologies and associated phase transitions driven by braiding processes in the phonon spectra of monolayer silicates, providing clear signatures for experimental verification. Topological phases of matter have revolutionised the fundamental understanding of band theory and hold great promise for next-generation technologies such as low-power electronics or quantum computers. Single-gap topologies have been extensively explored, and a large number of materials have been theoretically proposed and experimentally observed. These ideas have recently been extended to multi-gap topologies with band nodes that carry non-Abelian charges, characterised by invariants that arise by the momentum space braiding of such nodes. However, the constraints placed by the Fermi-Dirac distribution to electronic systems have so far prevented the experimental observation of multi-gap topologies in real materials. Here, we show that multi-gap topologies and the accompanying phase transitions driven by braiding processes can be readily observed in the bosonic phonon spectra of known monolayer silicates. The associated braiding process can be controlled by means of an electric field and epitaxial strain, and involves, for the first time, more than three bands. Finally, we propose that the band inversion processes at the Gamma point can be tracked by following the evolution of the Raman spectrum, providing a clear signature for the experimental verification of the band inversion accompanied by the braiding process.
Place, publisher, year, edition, pages
Springer Nature , 2022. Vol. 13, no 1, article id 423
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:kth:diva-307762DOI: 10.1038/s41467-022-28046-9ISI: 000745469500003PubMedID: 35058473Scopus ID: 2-s2.0-85123215201OAI: oai:DiVA.org:kth-307762DiVA, id: diva2:1636188
Note
QC 20220209
2022-02-092022-02-092023-07-24Bibliographically approved