Speaker: Mathieu Gibert
Abstract: Quantum vortices are a core element of superfluid dynamics and elusively
hold the keys to our understanding of energy dissipation in these systems. We show that
we can visualize these vortices in the canonical and higher-symmetry case of a stationary
rotating superfluid bucket. Using direct visualization, we quantitatively verify Feynman’s
rule linking the resulting quantum vortex density to the imposed rotational speed. We
make the most of this stable configuration by applying an alternative heat flux aligned
with the axis of rotation. Moderate amplitudes led to the observation of collective wave
mode propagating along the vortices, and high amplitudes led to quantum vortex
interactions. When increasing the heat flux, this ensemble of regimes defines a path
toward quantum turbulence in rotating 4He and sets a baseline to consolidate the
descriptions of all quantum fluids.
Ref: Peretti, C., Vessaire, J., Durozoy, É., & Gibert, M. (2023). Direct visualization of the
quantum vortex lattice structure, oscillations, and destabilization in rotating 4He. Science
Advances. https://doi.org/adh2899