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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We study the elastodynamics of a periodic metastructure incorporating adefect pair that enforces a parity-time (PT) symmetry due to a judiciouslyengineered imaginary impedance elements - one having energy amplification(gain) and the other having an equivalent attenuation (loss) mechanism. We showthat their presence affects the initial band structure of the periodicHermitian metastructure and leads to the formation of numerous exceptionalpoints (EPs) which are mainly located at the band edges where the local densityof modes is higher. The spatial location of the PT-symmetric defect serves asan additional control over the number of emerging EPs in the correspondingspectra as well as the critical non-Hermitian (gain/loss) strength required tocreate the first EP - a specific defect location minimizes the criticalnon-Hermitian strength. We use both finite element andcoupled-mode-theory-based models to investigate these metastructures, and use atime-independent second-order perturbation theory to further demonstrate theinfluence of the size of the metastructure and the PT-symmetric defect locationon the minimum non-Hermitian strength required to create the first EP in aband. Our findings motivate feasible designs for the experimental realizationof EPs in elastodynamic metastructures.

Emergence of Exceptional Points in Periodic Metastructures with Hidden PT-symmetric Defects