Superradiant droplet emission from parametrically excited cavities

Superradiance occurs when a collection of atoms exhibits cooperative, spontaneous emission of

photons at a rate that exceeds that of its component parts. Here, we reveal a similar phenomenon

in a hydrodynamic system consisting of a pair of vibrationally-excited cavities, coupled through

their common wavefield, that spontaneously emit droplets via interfacial fracture. We show that

the droplet emission rate of two coupled cavities is higher than the emission rate of two isolated

cavities. We further show that the amplified emission rate varies sinusoidally with distance between

the cavities, thus demonstrating a hydrodynamic phenomenon that captures the essential features

of superradiance in optical systems.