Faraday wave lattice as an elastic metamaterial

Posted by on May 22, 2016 in Bibliography, Core Bibliography | 0 comments

Domino, L., Tarpin, M., Patinet, S., & Eddi, A. (2016). Faraday wave lattice as an elastic metamaterial. arXiv preprint arXiv:1601.08024.

(Also on PhysRev E.)

Metamaterials enable the emergence of novel physical properties due to the existence of an underlying sub-wavelength structure. Here, we use the Faraday instability to shape the uid-air interface with a regular pattern. This pattern undergoes an oscillating secondary instability and exhibits spontaneous vibrations that are analogous to transverse elastic waves. By locally forcing these waves, we fully characterize their dispersion relation and show that a Faraday pattern presents an
e ffective shear elasticity. We propose a physical mechanism combining surface tension with the Faraday structured interface that quantitatively predicts the elastic wave phase speed, revealing that the liquid interface behaves as an elastic metamaterial.

Faraday wave lattice as an elastic metamaterial




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Revisiting time reversal and holography with spacetime transformations.

Posted by on Oct 12, 2015 in Bibliography, Core Bibliography | 0 comments

Bacot, V., Labousse, M., Eddi, A., Fink, M., & Fort, E. (2015). Revisiting time reversal and holography with spacetime transformations. arXiv preprint arXiv:1510.01277.

Wave control is usually performed by spatially engineering the properties of a medium. Because time and space play similar roles in wave propagation, manipulating time boundaries provides a complementary approach. Here, we experimentally demonstrate the relevance of this concept by introducing instantaneous time mirrors. We show with water waves that a sudden change of the effective gravity generates time-reversed waves that refocus at the source. We generalize this concept for all kinds of waves introducing a universal framework which explains the effect of any time disruption on wave propagation. We show that sudden changes of the medium properties generate instant wave sources that emerge instantaneously from the entire space at the time disruption. The time-reversed waves originate from these “Cauchy sources” which are the counterpart of Huygens virtual sources on a time boundary. It allows us to revisit the holographic method and introduce a new approach for wave control.


Instant Time Reversal

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Interaction of two walkers: Wave-mediated energy and force

Posted by on Sep 26, 2015 in Bibliography, Core Bibliography | 0 comments

Borghesi, C., Moukhtar, J., Labousse, M., Eddi, A., Fort, E., & Couder, Y. (2014). Interaction of two walkers: Wave-mediated energy and force. Physical Review E, 90(6), 063017.

A bouncing droplet, self-propelled by its interaction with the waves it generates, forms a classical wave-particle association called a “walker.” Previous works have demonstrated that the dynamics of a single walker is driven by its global surface wave field that retains information on its past trajectory. Here, we investigate the energy stored in this wave field for two coupled walkers and how it conveys an interaction between them. For this purpose, we characterize experimentally the “promenade modes” where two walkers are bound, and propagate together. Their possible binding distances take discrete values, and the velocity of the pair depends on their mutual binding. The mean parallel motion can be either rectilinear or oscillating. The experimental results are recovered analytically with a simple theoretical framework. A relation between the kinetic energy of the droplets and the total energy of the standing waves is established.



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Marcheurs, Dualité onde-particule et Mémoire de chemin

Posted by on Jun 1, 2013 in Bibliography, Core Bibliography, Thesis | 0 comments

“L’organisation du manuscrit est la suivante : dans le premier chapitre, nous rappelons les premieres experiences realisees avec les gouttes rebondissantes, en particulier les regimes ou elles sont statiques. Nous presentons egalement l’instabilite de Faraday qui permet d’expliquer le couplage entre goutte et ondes a l’origine des marcheurs. Leurs proprietes sont discutees, en particulier dans le cas des experiences de di raction. Dans un second chapitre, nous presentons le montage experimental ainsi que l’ensemble des techniques de mesure utilisees. Le troisieme chapitre est dedie a l’etude d’un analogue de l’e et tunnel pour les marcheurs. Le quatrieme est consacre a l’etude des ondes de surface generees par un marcheur, en particulier le lien avec l’instabilite de Faraday a l’origine de la memoire de chemin. En fin, dans le chapitre cinq, nous analysons la nature des trajectoires circulaires d’un marcheur soumis a une force orthogonale au mouvement. L’in uence de la memoire de chemin sur la quanti cation des rayons est presentee en detail, pour comprendre comment cet analogue macroscopique des niveaux de Landau se met en place avec des marcheurs.”

Eddi, A. (2011). Marcheurs, Dualité onde-particule et Mémoire de chemin (Doctoral dissertation, Université Paris-Diderot-Paris VII).


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