The superfluid transition of <sup>4</sup>He, a test case for finite-size scaling at a second-order phase transition
Francis M Gasparini; Mark O Kimball; Kevin P Mooney; Francis M Gasparini; Department of Physics, University at Buffalo, SUNY, USA; Mark O Kimball; Department of Physics, University at Buffalo, SUNY, USA; Kevin P Mooney; Department of Physics, University at Buffalo, SUNY, USA
Журнал:
Journal of Physics: Condensed Matter
Дата:
2001-05-28
Аннотация:
The second-order phase transition of <sup>4</sup>He from a normal fluid to a superfluid is ideally suited for studies of critical behaviour. In particular, effects of confinement have been studied recently to verify theoretical predictions of correlation-length scaling and calculations of specific scaling functions. These predictions are summarized for the specific heat and the superfluid density. The method of achieving confinement is discussed, as well as the measuring technique. The specific heat and the superfluid density in planar confinement are examined. It is found that the specific heat scales well on the normal side, and just as well on the superfluid side until the region of the specific heat maximum is reached. Here deviations from scaling are seen. It is possible that this behaviour is associated with the specific crossover in two dimensions. The superfluid fraction, which has been measured for the same type of confinement in two different ways, does not scale. Results of a calculation for the superfluid density to assess the role of the inhomogeneity induced by the van der Waals attraction at the confining walls are presented.
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