title: Dynamical phenomena: walking and orbiting droplets.
abstract: Small drops can bounce indefinitely on a bath of the same liquid if the container is oscillated vertically at a sufficiently high acceleration. Here we show that bouncing droplets can be made to 'walk' at constant horizontal velocity on the liquid surface by increasing this acceleration. This transition yields a new type of localized state with particle-wave duality: surface capillary waves emanate from a bouncing drop, which self-propels by interaction with its own wave and becomes a walker. When two walkers come close, they interact through their waves and this 'collision' may cause the two walkers to orbit around each other.
authors.affiliation: Matières et Systèmes Complexes, Université Paris 7 Denis Diderot, 75005 Paris, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Couder
authors.forename: S
authors.initials: S
authors.lastname: Protière
authors.forename: E
authors.initials: E
authors.lastname: Fort
authors.forename: A
authors.initials: A
authors.lastname: Boudaoud