2003/05/15 by Anna Maciołek, A. Maciolek, M. Krech +1 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Fluid Dynamics and Turbulent Flows #Material Dynamics and Properties #Quantum, superfluid, helium dynamics #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.69.036117
32 pages, 12 figures, submitted to the Phys. Rev. E
arxiv created 2003/05/15 · openalex publication_date 2004/03/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A lattice model of 3He-4He mixtures which takes into account the continuous rotational symmetry O(2) of the superfluid degrees of freedom of 4He is studied in the molecular-field approximation and by Monte Carlo simulations in three dimensions. In contrast to its two-dimensional version, for reasonable values of the interaction parameters the resulting phase diagram resembles that observed experimentally for 3He-4He mixtures, for which phase separation occurs as a consequence of the superfluid transition. The corresponding continuum Ginzburg-Landau model with two order parameters describing 3He-4He mixtures near tricriticality is derived from the considered lattice model. All coupling constants appearing in the continuum model are explicitly expressed in terms of the mean concentration of 4He, the temperature, and the microscopic interaction parameters characterizing the lattice system.