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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Photonic topological insulators exhibit bulk-boundary correspondence, whichrequires that boundary-localized states appear at the interface formed betweentopologically distinct insulating materials. However, many topological photonicdevices share a boundary with free space, which raises a subtle but criticalproblem as free space is gapless for photons above the light-line. Here, we usea local theory of topological materials to resolve bulk-boundary correspondencein heterostructures containing gapless materials and in radiative environments.In particular, we construct the heterostructure's spectral localizer, acomposite operator based on the system's real-space description that provides alocal marker for the system's topology and a corresponding local measure of itstopological protection; both quantities are independent of the material's bulkband gap (or lack thereof). Moreover, we show that approximating radiativeoutcoupling as material absorption overestimates a heterostructure'stopological protection. As the spectral localizer is applicable to systems inany physical dimension and in any discrete symmetry class, our results show howto calculate topological invariants, quantify topological protection, andlocate topological boundary-localized resonances in topological materials thatinterface with gapless media in general.

Classifying topology in photonic heterostructures with gapless environments