English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Plasmons, the collective excitations of electrons in the bulk or at thesurface, play an important role in the properties of materials, and havegenerated the field of Plasmonics. We report the observation of a highlyunusual acoustic plasmon mode on the surface of a three-dimensional topologicalinsulator (TI), Bi2Se3, using momentum resolved inelastic electron scattering.In sharp contrast to ordinary plasmon modes, this mode exhibits almost lineardispersion into the second Brillouin zone and remains prominent with remarkablyweak damping not seen in any other systems. This behavior must be associatedwith the inherent robustness of the electrons in the TI surface state, so thatnot only the surface Dirac states but also their collective excitations aretopologically protected. On the other hand, this mode has much smaller energydispersion than expected from a continuous media excitation picture, which canbe attributed to the strong coupling with surface phonons.

Anomalous Acoustic Plasmon Mode from Topologically Protected States