Triplon modes of puddles.
Free fluctuations of the contact line of large drops ("puddles") of wavelength lambda > kappa(-1), the capillary length, cannot be seen on a solid substrate because even a small but finite hysteresis is enough to block these slow modes. We show here that vertical vibrations of the substrate (at frequency omegaE, acceleration Lambda) above a threshold amplitude Lambda(c) release the line and excite contour oscillations (triplons). We observe harmonic modes and parametric excitations at omegaE/2. We construct the phase diagram (Lambda, omegaE) of these subharmonic modes and we study their growth dynamics: they slow down near the threshold of the contour instability.
Noblin
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Physico-Chimie Curie, UMR 168 Institut Curie/CNRS, 11 rue Pierre et Marie Curie 75231 Cedex 05 Paris, France.
Buguin
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A
Brochard-Wyart
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F