Mapping propagation of collective modes in Bi₂Se₃ and Bi₂Te_2.2Se_0.8 topological insulators by near-field terahertz nanoscopy.

ABSTRACT: Near-field microscopy discloses a peculiar potential to explore novel quantum state of matter at the nanoscale, providing an intriguing playground to investigate, locally, carrier dynamics or propagation of photoexcited modes as plasmons, phonons, plasmon-polaritons or phonon-polaritons. Here, we exploit a combination of hyperspectral time domain spectroscopy nano-imaging and detectorless scattering near-field optical microscopy, at multiple terahertz frequencies, to explore the rich physics of layered topological insulators as Bi₂Se₃ and Bi₂Te_2.2Se_0.8, hyperbolic materials with topologically protected surface states. By mapping the near-field scattering signal from a set of thin flakes of Bi₂Se₃ and Bi₂

SUBMITTER: Pogna EAA 

PROVIDER: S-EPMC8602307 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature