In fermionic superfluids, the vortex core differs fundamentally from that in bosonic condensates. While vortex cores in Bose–Einstein condensates are empty at zero temperature, at strongly interacting unitary Fermi gases (UFG) and BCS regimes vortices host localized quasiparticles occupying discrete Caroli–de Gennes–Matricon levels. These bound states give rise to a finite core density and enhanced dissipation in vortex motion, which becomes stronger toward the BCS limit.
This microscopic structure strongly influences vortex interactions with external potentials, impurities, and boundaries, making the mechanisms of vortex pinning and unpinning an important open question in ultracold Fermi-gas theory. Clarifying this link is essential for understanding dissipation, vortex dynamics, and quantum turbulence in systems from ultracold gases to neutron star interiors.
The thesis will involve theoretical and numerical simulations studies, employing Bogoliubov–de Gennes and time-dependent density functional simulations.
Supervisor: Prof. Klejdja Xhani — klejdja.xhani@polito.it