title: Competition between thermal fluctuations and disorder in the crystallization of 4He in aerogel.
abstract: 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.
authors.affiliation: Department of Condensed Matter Physics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Nomura
authors.forename: Aiko
authors.initials: A
authors.lastname: Osawa
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Mimori
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Ueno
authors.forename: Haruko
authors.initials: H
authors.lastname: Kato
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Okuda