Séminaire de l'INPHYNI: Giorgio Krstulovic

Superfluids are highly peculiar fluids characterised by the complete absence of viscosity; the most common examples include low-temperature helium (below 2.1 K) and atomic Bose–Einstein condensates. They are macroscopic manifestations of quantum mechanics and are routinely studied in the lab today. Superfluids concentrate vorticity into extremely thin filaments, where circulation is quantised.  Such filaments are topological defects known as quantum vortices. Despite their inviscid character and quantum origin, superfluids share many aspects with high-Reynolds-number classical flows and can be seen as the skeleton of turbulent flows.

In this talk, I will provide an overview of our current understanding of quantum turbulence. I will begin with a brief introduction to superfluids, outlining the state-of-the-art experiments in the field and the challenges we encounter in modelling the dynamics of quantum vortices and quantum turbulence. Then, I will follow a journey along scales, presenting theoretical and numerical results that range from the process of vortex reconnection to a fine comparison between classical and quantum turbulence, where the dynamics of intricate vortex tangles lead to very complex statistics. Throughout the talk, I will highlight the differences and similarities between classical and quantum fluids, uncovering the universal phenomena they share.