Fermer le menu

Agenda

 

Mathieu Gibert, équipe HELFA, présentera
le séminaire mensuel NÉEL

Mardi 16 janvier 2024 à 9h30

Salle des séminaires – Bâtiment A

 

Titre : Visualisation directe de la structure, des oscillations et de la déstabilisation du réseau de vortex quantiques dans le 4He en rotation

Résumé

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/10.1126/sciadv.adh2899