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Lossy phononic metamaterials for valley nonreciprocity
Shunda Yin1, Qiuyan Zhou1, Yuxiang Xi1
1Key Laboratory of Artificial Micro- and Nanostructures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, China.
Nature Communications
|March 4, 2026
Summary
Researchers demonstrate how coupling loss in phononic metamaterials can control valley dynamics, enabling unidirectional transport and boundary-localized states for valley-based devices.
Area of Science:
- Condensed Matter Physics
- Metamaterials Science
- Non-Hermitian Physics
Background:
- Non-Hermitian physics, marked by complex band spectra, has revolutionized condensed matter and metamaterials.
- Nonreciprocity combined with non-Hermitian gain can control valley dynamics, enabling phenomena like amplified topological whispering gallery modes for acoustic lasing.
Purpose of the Study:
- To reveal how coupling loss can manipulate valley degrees of freedom in phononic metamaterials.
- To explore the interplay between non-Hermitian physics and valley physics.
Main Methods:
- Theoretical modeling of phononic metamaterials.
- Experimental validation of predicted phenomena.
- Investigation of valley nonreciprocity effects.
Main Results:
- Demonstrated unidirectional transport of valley bulk states, functioning as a valley filter.
- Observed valley-dependent skin effects, localizing bulk states at opposite boundaries.
- Showcased valley-projected edge states with boundary-dependent lifetimes, enabling anomalous beam routing.
Conclusions:
- Coupling loss offers a simple method to control valley dynamics in phononic metamaterials.
- Findings provide insights into non-Hermitian and valley physics interplay.
- Opens avenues for valley-based device applications.
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