Download Rotating Superfluid He- A in Parallel Plates

Rotating Superfluid 3 He-A in Parallel Plates
Minoru Yamashitab , Ken Izuminaa , Akira Matsubarad, Yutaka Sasakid, Osamu Ishikawac, Takeo Takagie ,
Minoru Kubotaa , and Takao Mizusakib
a
Institute for Solid State Physics, The University of Tokyo, Chiba 277-8581, Japan
Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
c
Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
d
Research Center for Low Temperature and Materials Sciences, Kyoto University, Kyoto 606-8502, Japan
e
Department of Applied Physics, Fukui University, Fukui 910-8507, Japan
b
We have measured NMR spectra of 3 He-A phase restricted between parallel plates under rotation |Ω| ≤
6.28 rad/s, using a rotating cryostat at ISSP. The sample was consisted of 110 stacks of disk-shaped
spacing of 12.5 µm thickness and 1.5 mm radius, which were connected to a bulk superfluid through
0.3 mm channels. Because of the anisotropy of 3 He-A and the narrow gap, we can align the ` texture
perpendicular to the plates and can keep ` parallel to a magnetic field, H, even for H = 27 mT.
Measurements were done by cw-NMR as a function of rotation speed Ω. Both axis of H and Ω are
perpendicular to the sample plates. We observed a very narrow spectrum with negative frequency shift,
which shows that these gaps and the `-texture are well-designed. Above 1.0 rad/s, a satellite signal
appeared near the Larmor frequency. We found that, by a calculation of the texture and the NMR
spectrum under rotation, the signal can be explained by the spin wave trapped by a `-texture bent by a
normal flow induced by rotation.
Sorting category: Ab Quantum gases, fluids and solids
Keywords: superfluidity, helium3, vortex
LT1388