Bose–Einstein condensation in a decorated lattice: an application to the problem of supersolid He

• Veröffentlicht in: Физика низких температур
• Datum: 2008
• Hauptverfasser: Fil, D.V., Shevchenko, S.I.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2008
• Schlagworte: Твердый гелий
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/116910
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Bose–Einstein condensation in a decorated lattice:
 an application to the problem of supersolid He / D.V. Fil, S.I. Shevchenko // Физика низких температур. — 2008. — Т. 34, № 4-5. — С. 440–446. — Бібліогр.: 13 назв. — англ.

The Bose–Einstein condensation of vacancies in a three-dimensional decorated lattice is considered. The
 model describes possible scenario of superfluidity of solid helium, caused by the presence of zero-point vacancies
 in a dislocation network. It is shown that the temperature of Bose–Einstein condensation decreases
 under increase of the length of the network segments, and the law of decrease depends essentially on the
 properties of the vertexes of the network. If the vertexes correspond to barriers with a small transparency,
 the critical temperature is inversely as the square of the length of the segment. On the contrary, if the vertexes
 correspond to traps for the vacancies (it is energetically preferable for the vacancies to be localized at
 the vertexes), an exponential lowering of the temperature of transition takes place. The highest temperature
 of Bose–Einstein condensation is reached in the intermediate case of vertexes with large transparency, but in
 the absence of tendency of localization at them. In the latter case the critical temperature is inversely as the
 length of the segment.