Speaker
Description
Fermionic p-wave superfluid 3He is known to host various kinds of quantized vortices, including half-, single- and double-quantum. Regular motion of such vortices through the fluid is well understood: It is governed by the mutual friction, which originates in interaction of vortex-core-bound fermions with bulk quasiparticles. I present three examples of less usual vortex dynamics observed experimentally: 1) In the polar phase of superfluid 3He, containing nodal line in the energy spectrum, vortices are easily pinned in the confining matrix of solid nanostrands, used to stabilize the polar phase. This may provide the best laboratory model for vortices in a neutron star interacting with the crust. 2) Dynamically driven transition from vortex lines to vortex sheets in the A phase, where moving vortex structures create synthetic electromagnetic field for Bogoliubov quasiparticles, which are Weyl fermions in the A phase. 3) Development of Kelvin waves (KWs) and KW-turbulence on vortices in the B phase, where the gap in the energy spectrum allows suppression of bulk quasiparticles and mutual friction at the lowest temperatures. KWs are believed to be an essential energy transfer mechanism in the ultra-low-temperature quantum turbulence. In a Fermi superfluid, KWs additionally interact with the core-bound states, overheating them.