12 research outputs found
Phase diagram of superfluid 3He in "nematically ordered" aerogel
Results of experiments with liquid 3He immersed in a new type of aerogel are
described. This aerogel consists of Al2O3 strands which are nearly parallel to
each other, so we call it as a "nematically ordered" aerogel. At all used
pressures a superfluid transition was observed and a superfluid phase diagram
was measured. Possible structures of the observed superfluid phases are
discussed.Comment: 6 pages, 8 figures. Submitted to Pis'ma v ZhETF (JETP Letters
Half - Quantum Vortices
Unlike to superfluid He the superfluid He-A support the existence of
vortices with half quantum of circulation as well as single quantum vortices.
The singular single quanta vortices as well as nonsingular vortices with 2
quanta of circulation have been revealed in rotating He-A. However, the
half quantum vortices in open geometry always possess an extra energy due to
spin-orbit coupling leading to formation of domain wall at distances larger
than dipole length from the vortex axis.
Fortunately the same magnetic dipole-dipole interaction does not prevent the
existence of half-quantum vortices in the polar phase of superfluid He
recently discovered in peculiar porous media "nematically ordered" aerogel.
Here we discuss this exotic possibility.
The discoveries of half-quantum vortices in triplet pairing superconductor
SrRuO as well in the exciton-polariton condensates are the other parts
of the story about half-quantum vortices also described in the paper.Comment: 6 pages, no figure