The features of the collective modes in aerogels filled with superfluid helium

Autor:	G. A. Sheshin, E. Ya. Rudavskii, Sh. E. Kekutia, N. D. Chkhaidze, V. K. Chagovets, Norbert Mulders, A. A. Zadorozhko
Rok vydání:	2009
Předmět:	Matrix (mathematics) Materials science Physics and Astronomy (miscellaneous) Condensed matter physics Condensed Matter::Other General Physics and Astronomy Aerogel Квантовые жидкости и квантовые кpисталлы Hydrodynamic theory Porosity Tortuosity Superfluid helium-4
Zdroj:	Low Temperature Physics. 35:752-756
ISSN:	1090-6517 1063-777X
DOI:	10.1063/1.3253393
Popis:	The velocity of fast and slow collective modes of 90, 94 and 98% porosity aerogels filled with superfluid helium were measured by means of low-frequency resonant technique at temperatures 0.5–2.5 K. The temperature dependences of velocities of both modes are compared with the hydrodynamic theory which was modified taking into account the mobility of the aerogel matrix, porosity of media and tortuosity of an acoustic way. It has been found that the fast and slow modes in an aerogel are coupled much stronger than the first and second sounds in bulk He II.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b42acc35a33ebb1a13ba479b90f61ca3 https://doi.org/10.1063/1.3253393 Zobrazit plný text záznamu