LTL E97023

Vortex Nucleation in Quench-Cooled Superfluid Phase Transition

V.M. Ruutu, V.B. Eltsov, M. Krusius, Yu.G. Makhlin, B. Plaçais, and G.E. Volovik

Low Temperature Laboratory, Helsinki University of Technology, 02150 Espoo, Finland. (April 14, 1997)

In rotating superfluid 3He-B the absorption of thermal neutrons can be used to heat locally a 10 micron-size volume into normal phase. When the heated bubble cools back in a few microsecs, vortex lines are observed to form. We record with NMR the number of lines per absorption event as a function of the superflow velocity. We find that the vortices are initially formed as rings within the bubble. Their number agrees with a simulation calculation of the escape of vortex loops from a random network, which is nucleated by the Kibble-Zurek mechanism in a very rapid phase transition.

PACS numbers: 05.70.Fh, 98.80.Cq, 67.40.Vs, 29.40.Ym

FTP:

file: VortexNucl.pdf (416k)