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Abstracts
I4.2
NMR studies of superfluid polar phase of superfluid
3
He
Dmitriev V.V.(1), Soldatov A.A.(1,2), Yudin A.N.(1)
1) P.L. Kapitza Institute for Physical Problems of RAS, 119334 Moscow, Russia
2) Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
We report results of NMR experiments in superfluid polar phase of 3He. This
phase is not realized in bulk
3
He, but can be stabilized in
3
He confined in a
new type of aerogel (nafen) which strands are nearly parallel to one another. In
our experiments the polar phase was observed in all used samples of nafen with
porosities from 98% down to 77%. It was found that the region of existence of
this phase essentially depends on nafen porosity, pressure and on
4
He coverage
of the nafen strands. NMR properties of the polar phase and influence of spin
supercurrents on the spin dynamics were investigated. Possible future experiments
will be also discussed in the talk.
I4.3
The A-B transition for superfluid
3
He confined to a 1.08 micrometer
tall geometry
Zhelev, N. (1), Abhilash, T.S.(1), Smith, E.N.(1), Bennett, R.G.(1), Rojas, X.(2),
Saunders, J. (2), and Parpia, J.M. (1)*
1) Department of Physics, Cornell University, Ithaca, NY, 14853 USA
2) Department of Physics, Royal Holloway University of London, Egham, TW20
0EX Surrey, United Kingdom
Motivated by recent experimental and theoretical work, we confine superfluid
3
He to a 1.08 micron thick nanofluidic cavity incorporated into the head of a
torsion pendulum. For measurements between 0.1 and 5.6 bar we observe that
the A phase is always interspersed between the B phase and the normal state
and the superfluid fraction of the A phase is always greater than that of the B
phase which is bulk-like. The dissipation is greater in the B phase than the A
phase contrary to bulk behavior. Despite clean surfaces that do not pin the phase
boundary, the non-monotonic supercooling of the A phase is seen to be much
smaller than in the bulk. Our experiment did not observe the presence of the
striped phase, likely due to bowing of the cell cavity at pressure.
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