Publication: Deep-subwavelength holey acoustic second-order topological insulators
Loading...
Identifiers
Publication date
2019-12-06
Defense date
Advisors
Tutors
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley-VCH Verlag GmbH & Co.
Impact
Export
Abstract
Higher-order topological insulators (HOTIs) belong to a new class of materials with unusual topological phases. They have garnered considerable attention due to their capabilities in confining energy at the hinges and corners, which is entirely protected by the topology, and have thus become attractive structures for acoustic wave studies and control. However, for most practical applications at audible and low frequencies, compact and subwavelength implementations are desirable in addition to providing robust guiding of sound beyond a single-frequency operation. Here, a holey HOTI capable of sustaining deeply confined corner states 50 times smaller than the wavelength is proposed. A remarkable resilience of these surface-confined acoustic states against defects is experimentally observed, and topologically protected sound is demonstrated in three different frequency regimes. Concerning this matter, the findings will thus have the capability to push forward exciting applications for robust acoustic imaging way beyond the diffraction limit.
Description
Keywords
Deep-Subwavelength Acoustic Imaging, Phononic crystals, Second-order topological insulators, Spoof surface acoustic waves, Topological corner states
Bibliographic citation
Advanced Materials , 31(49), 1904682, Dec. 2019, 7 pp.