Wave Turbulence in Superfluid 4He: Energy Cascades & Rogue Waves in the Laboratory.

Recent work on second sound acoustic turbulence in superfluid ⁴He is reviewed. Observations of forward and inverse energy cascades are described. The onset of the inverse cascade occurs above a critical driving energy and it is accompanied by giant waves that constitute an acoustic analogue of the rogue waves that occasionally appear on the surface of the ocean. The theory of the phenomenon is outlined and shown to be in good agreement with the experiments. [ABSTRACT FROM AUTHOR]