Symmetry-Protected Moiré Band Engineering and Enhanced Electron-Phonon Coupling in Xe/Bi<sub>2</sub>Se<sub>3</sub> Superlattices: Path to Topological Superconductivity.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41954561.
- Also identified by DOI 10.1021/acsnano.5c20111 and PMC identifier 13104177.
- 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
Observation of superconductivity, magnetism, and correlated insulating phases driven by the moiré potential in twisted graphene bilayer has opened the exciting new field of "twistronics". Even richer physics is expected if moiré superlattice could be generated on topological insulators; however, until now, experimental studies have been scarce. Here, we demonstrate topological moirés generated by adsorbing a monolayer of noble gas on a topological insulator. By angle-resolved photoemission spectroscopy, we show that the moiré potential replicates the topological surface state and affects it in a way fundamentally different from the trivial states. Replicated Dirac cones generally avoid crossings, except at the time-reversal invariant momenta that remain gapless. This creates van Hove singularities at the moiré Brillouin zone corners, providing the mechanism of enhancing correlations. Indeed, we observe a strong enhancement of the electron-phonon coupling strength that, if properly tuned, might lead to topological superconductivity and Majorana Fermions.