Asymmetric acoustic energy transport in non-Hermitian metamaterials
| Autor: | Demetrios N. Christodoulides, Ramathasan Thevamaran, Edwin L. Thomas, Eleana Makri, Richard Massey Branscomb, Paul Anzel, Tsampikos Kottos |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Acoustics and Ultrasonics Acoustics FOS: Physical sciences Physics::Optics Cloaking Metamaterial Applied Physics (physics.app-ph) Physics - Applied Physics 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Signal Vibration Nonlinear system Arts and Humanities (miscellaneous) 0103 physical sciences Transmittance High harmonic generation 010306 general physics 0210 nano-technology Optics (physics.optics) Physics - Optics Acoustic resonance |
| Zdroj: | The Journal of the Acoustical Society of America. 146:863-872 |
| ISSN: | 0001-4966 |
| DOI: | 10.1121/1.5114919 |
| Popis: | The ability to control and direct acoustic energy is essential for many engineering applications such as vibration and noise control, invisibility cloaking, acoustic sensing, energy harvesting, and phononic switching and rectification. The realization of acoustic regulators requires overcoming fundamental challenges inherent to the time-reversal nature of wave equations. Typically, this is achieved by utilizing either a parameter that is odd-symmetric under time-reversal or by introducing passive nonlinearities. The former approach is power consuming while the latter has two major deficiencies: it has high insertion losses and the outgoing signal is harvested in a different frequency than that of the incident wave due to harmonic generation. Here, a unique approach is adopted that exploits spatially distributed linear and nonlinear losses in a fork-shaped resonant metamaterials. This compact metamaterial design demonstrates asymmetric acoustic reflectance and transmittance, and acoustic switching. In contrast to previous studies, the non-Hermitian metamaterials exhibit asymmetric transport with high frequency purity of the outgoing signal. |
| Databáze: | OpenAIRE |
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