Competition between thermal fluctuations and disorder in the crystallization of 4He in aerogel.
The dynamical transition in the crystallization of 4He in aerogel has been investigated by direct visualization and dynamical phase diagrams have been determined. The crystal-superfluid interface in aerogel advances via creep at high temperatures and avalanches at low temperatures. The transition temperature is higher at a higher interface velocity and lower in higher porosity aerogels. The transition is due to competition between thermal fluctuations and disorder for the crystallization process.
Nomura
Ryuji
R
Department of Condensed Matter Physics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo, Japan.
Osawa
Aiko
A
Mimori
Tomohiro
T
Ueno
Ken-ichi
K
Kato
Haruko
H
Okuda
Yuichi
Y