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

Phononic metamaterials have attracted extensive attention since they areexibly adjustable to control the phonon transmission. In this work, we study aone-dimensional phononic metamaterial, made of mechanical resonant oscillatorsand chiral couplings. We show that by design, the oscillator mass andinter-oscillator coupling, although both are positive naturally, can be eithersingle negative or double negative effectively within a certain frequencyrange. At the frequency where the effective mass and coupling are bothinfinite, a flat band emerges that will induce an extremely high density ofstates. At the critical point of band degeneracy, a Dirac-like point emergeswhere both effective mass and the inverse of effective coupling aresimultaneously zero, so that zero index is realized for phonons. Moreover, thephononic topological phase transition is observed that the phononic band gapswitches between single mass-negative and single coupling-negative regime. As aconsequence, a topological interface state is identified, well explained by thetheory.

Zero-index and Topology in 1D Phononic Metamaterials with Negative Mass and Negative Coupling