Cluster phases of penetrable rods on a line

Abstract

Phase transitions are uncommon among homogenous one-dimensional fluids of classical particles owing to a general non-existence result due to van Hove. A way to circumvent van Hove's theorem is to consider an interparticle potential that is finite everywhere. Of this type is the generalized exponential model of index 4 (GEM4 potential), a model interaction which in three dimensions provides an accurate description of the effective pair repulsion between dissolved soft macromolecules (e.g., flexible dendrimers). Using specialized free-energy methods, I reconstruct the equilibrium phase diagram of the one-dimensional GEM4 system, showing that, apart from the usual fluid phase at low densities, it consists of an endless sequence of {\em cluster fluid phases} of increasing pressure, having a sharp crystal appearance for low temperatures. The coexistence line between successive phases in the sequence invariably terminates at a critical point. Focussing on the first of such transitions, I show that the growth of the 2-cluster phase from the metastable ordinary fluid is extremely slow, even for large supersaturations. Finally, I clarify the apparent paradox of the observation of an activation barrier to nucleation in a system where, due to the dimensionality of the hosting space, the critical radius is expected to vanish.

24 pages, 17 figures

References in corpus (7)

• Why do ultrasoft repulsive particles cluster and crystallize? Analytical results from density functional theory
• Systematic Improvement of Classical Nucleation Theory
• Computer Assembly of Cluster-Forming Amphiphilic Dendrimers
• Anomalous phase behavior of a soft-repulsive potential with a strictly monotonic force
• The zero-temperature phase diagram of soft-repulsive particle fluids
• On the accuracy of the melting curves drawn from modelling a solid as an elastic medium
• [N]pT ensemble and finite-size scaling study of the GEM-4 critical isostructural transition

Cited by in corpus (5)

• Hexatic phase and cluster crystals of two-dimensional GEM4 spheres
• Ground state of weakly repulsive soft-core bosons on a sphere
• Quantum Critical Behavior of One-Dimensional Soft Bosons in the Continuum
• Emergence of an Ising critical regime in the clustering of 1D soft matter revealed through string variables
• Evolution of static and dynamical density correlations in a one-dimensional soft-core gas from the Tonks-Girardeau limit to a clustering fluid