Critical scaling properties at the superfluid transition of He-4 in aerogel
2006 (English)In: Physical Review Letters, ISSN 0031-9007, Vol. 97, no 22, 225702- p.Article in journal (Refereed) Published
We study the superfluid transition of He-4 in aerogel by Monte Carlo simulations and finite size scaling analysis. Aerogel is a highly porous silica glass, which we model by a diffusion limited cluster aggregation model. The superfluid is modeled by a three dimensional XY model, with excluded bonds to sites on the aerogel cluster. We obtain the correlation length exponent nu=0.73 +/- 0.02, in reasonable agreement with experiments and with previous simulations. For the heat capacity exponent alpha, both experiments and previous simulations suggest deviations from the Josephson hyperscaling relation alpha=2-d nu. In contrast, our Monte Carlo results support hyperscaling with alpha=-0.2 +/- 0.05. We suggest a reinterpretation of the experiments, which avoids scaling violations and is consistent with our simulation results.
Place, publisher, year, edition, pages
2006. Vol. 97, no 22, 225702- p.
Aerogels; Computer simulation; Fused silica; Monte Carlo methods; Phase transitions; Specific heat; Correlation length; Hyperscaling relation; Porous silica glass; Superfluid transition; Superfluid helium
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-6907DOI: 10.1103/PhysRevLett.97.225702ISI: 000242538700034ScopusID: 2-s2.0-34547647871OAI: oai:DiVA.org:kth-6907DiVA: diva2:11752
QC 201008112007-03-212007-03-212012-03-21Bibliographically approved