Postponing the dynamical transition density using competing interactions
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ORIGINAL PAPER
Postponing the dynamical transition density using competing interactions Patrick Charbonneau1,2 · Joyjit Kundu2 Received: 19 April 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Systems of dense spheres interacting through very short-ranged attraction are known from theory, simulations and colloidal experiments to exhibit dynamical reentrance. Their liquid state can thus be fluidized at higher densities than possible in systems with pure repulsion or with long-ranged attraction. A recent mean-field, infinite-dimensional calculation predicts that the dynamical arrest of the fluid can be further delayed by adding a longer-ranged repulsive contribution to the short-ranged attraction. We examine this proposal by performing extensive numerical simulations in a three-dimensional system. We first find the short-ranged attraction parameters necessary to achieve the densest liquid state, and then explore the parameter space for an additional longer-ranged repulsion that could further enhance reentrance. In the family of systems studied, no significant (within numerical accuracy) delay of the dynamical arrest is observed beyond what is already achieved by the short-ranged attraction. Possible explanations are discussed. Keywords Disorder systems · Glass · Dynamical transition · Square-well · Square-shoulder · Dynamical criticality
1 Introduction Particles with short-ranged attractive and long-ranged repulsive (SALR) interactions can form fairly elaborate structures [1–9]. Despite the spherical symmetry of their pair interaction potential, at low temperatures these models assemble into exotic ordered and disordered mesophases, and their structural richness has clear dynamical consequences, even in the disordered phase at low and intermediate densities [10–12]. A recent theoretical proposal suggests that certain SALR models exhibit unusual dynamical features in the very dense fluid regime as well [13]. Maimbourg et al. [13]’s extension of a high-dimensional treatment of the This article is part of the Topical Collection: In Memoriam of Robert P. Behringer. * Joyjit Kundu [email protected] Patrick Charbonneau [email protected] 1
Department of Chemistry, Duke University, Durham, NC, 27708, USA
Department of Physics, Duke University, Durham, NC 27708, USA
2
glass transition [14–16] suggests that certain SALR models should display a very pronounced dynamical reentrance upon changing temperature. More precisely, their theoretical analysis suggests that a carefully chosen high-density SALR system that is glassy at low temperature should, upon heating, first melt and then become dynamically arrested once again, all while remaining completely disordered, i.e., without crystallizing. On its own, such reentrance is not exceptional. The phase behavior of systems with square-well or with square shoulder interaction were first shown to exhibit multiple dynamically arrested phases leading to high-order singularities. These dynamical anomalies were proposed by mode
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