Séminaire de l'INPHYNI: Mathieu Gibert (Grenoble)

  • Culture scientifique
Publié le 24 novembre 2023 – Mis à jour le 20 mars 2024
Date(s)

le 26 mars 2024

Café : 15h
Séminaire: 15h15
Lieu(x)
Institut de Physique de Nice

Direct visualization of the quantum vortex lattice structure, oscillations, and destabilization in rotating 4 He

Seminars of the Institut de Physique de Nice,

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 sho  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