Abstract:
:Topological mechanical metamaterials are artificial structures whose unusual properties are protected very much like their electronic and optical counterparts. Here, we present an experimental and theoretical study of an active metamaterial--composed of coupled gyroscopes on a lattice--that breaks time-reversal symmetry. The vibrational spectrum displays a sonic gap populated by topologically protected edge modes that propagate in only one direction and are unaffected by disorder. We present a mathematical model that explains how the edge mode chirality can be switched via controlled distortions of the underlying lattice. This effect allows the direction of the edge current to be determined on demand. We demonstrate this functionality in experiment and envision applications of these edge modes to the design of one-way acoustic waveguides.
journal_name
Proc Natl Acad Sci U S Aauthors
Nash LM,Kleckner D,Read A,Vitelli V,Turner AM,Irvine WTdoi
10.1073/pnas.1507413112subject
Has Abstractpub_date
2015-11-24 00:00:00pages
14495-500issue
47eissn
0027-8424issn
1091-6490pii
1507413112journal_volume
112pub_type
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