2006/11/30 by Fabio Mezzacapo, Massimo Boninsegni · 3 citations
Physics and Astronomy · #Advanced Chemical Physics Studies #Cold Atom Physics and Bose-Einstein Condensates #Quantum, superfluid, helium dynamics #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreva.75.033201
published as Phys. Rev. A 75, 033201 (2007) · 11 pages, 16 figures
arxiv created 2007/03/14 · openalex publication_date 2007/03/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present results of a theoretical study of para-H2 (p\text\ensuremath-H2) and ortho-D2 (o\text\ensuremath-D2) clusters at low temperature (0.5\phantom\rule0.3em0exK\ensuremath\leqslantT\ensuremath\leqslant3.5\phantom\rule0.3em0exK) based on path integral Monte Carlo simulations. Clusters of N\ensuremath\leqslant21 p\text\ensuremath-H2 molecules are nearly entirely superfluid at T\ensuremath\leqslant1\phantom\rule0.3em0exK. For 22\ensuremath\leqslantN\ensuremath\leqslant30, the superfluid response displays strong variations with N, reflecting structural changes that occur on adding or removing even a single molecule. Some clusters in this size range display quantum melting, going from solidlike to liquidlike as T\ensuremath→0. Melting is caused by quantum exchanges of molecules. The largest p\text\ensuremath-H2 cluster for which a significant superfluid response is observed comprises N=27\phantom\rule0.3em0exmolecules. Evidence of a finite superfluid response is presented for o\text\ensuremath-D2 clusters of size up to N=14. Magic numbers are observed, at which both types of clusters feature pronounced stability.