Dynamics of superfluid vorticity in nondissipative processes

Ertugrul Demircan

Makoto Tsubota, Hideki Yoneda

E. K. Dahl, Egor S. Babaev, Asle Sudbø

We study the evolution of rotational response of a statistical mechanical model of two-component superfluid with a nondissipative drag interaction as the system undergoes a transition into a paired superfluid phase at finite temperature. The transition manifests itself in a change of (i) vortex-lattice symmetry and (ii) nature of the vortex state. Instead of a vortex lattice, the system forms a highly disordered tangle which constantly undergoes merger and reconnecting processes involving different types of vortices with a ``hidden'' breakdown of translation symmetry.

Carlos Wexler

Paul M. Walmsley, А. А. Левченко, Andrei I. Golov

R. Blaauwgeers, V. B. Eltsov, Georg Eska +6 more

The first realization of instabilities in the shear flow between two superfluids is examined. The interface separating the A and B phases of superfluid 3He is magnetically stabilized. With uniform rotation we create a state with discontinuous tangential velocities at the interface, supported by the difference in quantized vorticity in the two phases. This state remains stable and nondissipative to high relative velocities, but finally undergoes an instability when an interfacial mode is excited and some vortices cross the phase boundary. The measured properties of the instability are consistent with the classic Kelvin-Helmholtz theory when modified for two-fluid hydrodynamics.