Dissipation mechanisms near the superfluid 3He transition in aerogel.
We have investigated the dissipation (Q-1) using the torsion pendulum technique for pure 3He and 3He-4He mixtures in silica aerogel near the 3He superfluid transition (T(c)) in aerogel. With pure 3He the Q-1 decreases at the onset of superfluidity. When phase separated 3He-4He mixtures are introduced into the aerogel, the Q-1 does not decrease as rapidly and eventually increases for the highest 4He content. We provide a model for the related attenuation of transverse sound alpha that takes into account elastic and inelastic scattering processes and exhibits a decrease in alpha at T(c).
Golov
A I
AI
Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
Einzel
D
D
Lawes
G
G
Matsumoto
K
K
Parpia
J M
JM