School of Mathematics, Statistics and Physics

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Researchers realise 70 year old theory of turbulence in superfluids

Dr Andrew Groszek's work on superfluid turbulence has been published in the journal Science

Congratulations to Research Associate Dr Andrew Groszek, whose work on vortex clustering in superfluid turbulence --- completed during a previous position at Monash University, Australia --- has now been published in the journal Science.

Unlike normal liquids, superfluids directly exhibit their underlying quantum-mechanical nature. For instance, they flow without viscosity; once stirred into motion they tend to remain in motion forever. Another peculiar feature is that rotation in a thin layer of superfluid appears as a swarm of clockwise- and anticlockwise-turning mini-whirlpools called quantum vortices.

As long ago as 1949, Lars Onsager predicted that turbulence in such a thin layer of superfluid would cause similarly-turning quantum-vortices to cluster together into large rotating structures. While this idea has informed subsequent developments in the theory of classical fluid turbulence, a direct realization of the phenomenon in a superfluid has remained elusive for 70 years.

Recently Andrew and collaborators combined detailed theoretical modelling with advanced ultra-cold atomic gas experiments, performed at Monash University, Australia, in order to finally realize and characterize this long-predicted phenomenon. At the same time, a second group of collaborators were able to independently realize and characterize the same phenomenon in an experiment performed at the University of Queensland, Australia. The results of both groups, both published in Science, provide long-awaited experimental confirmation of Onsager's prediction and point the way to future experiments on superfluid turbulence in ultra-cold atomic gases.

https://science.sciencemag.org/content/364/6447/1267

https://science.sciencemag.org/content/364/6447/1264

Vortex clustering in superfluid turbulence

published on: 11 July 2019