Issue
EPL
Volume 86, Number 1, April 2009
Article Number 10001
Number of page(s) 6
Section General
DOI http://dx.doi.org/10.1209/0295-5075/86/10001
Published online 08 April 2009
EPL, 86 (2009) 10001
DOI: 10.1209/0295-5075/86/10001

Compressing nearly hard sphere fluids increases glass fragility

L. Berthier1 and T. A. Witten2

1   Laboratoire des Colloïdes, Verres et Nanomatériaux, UMR 5587, Université Montpellier II and CNRS 34095 Montpellier, France, EU
2   James Franck Institute and Department of Physics, The University of Chicago - 929 E. 57th Street, Chicago, IL 60637, USA

ludovic.berthier@lcvn.univ-montp2.fr

received on 23 February 2009; accepted in final form by L. F. Cugliandolo on 11 March 2009; published April 2009
published online 8 April 2009

Abstract
We use molecular dynamics to investigate the glass transition occurring at large volume fraction, $\varphi$, and low temperature, T, in assemblies of soft repulsive particles. We find that equilibrium dynamics in the ($\varphi$, T)-plane obey a form of dynamic scaling in the proximity of a critical point at T = 0 and $\varphi=\varphi_{0}$, which should correspond to the ideal glass transition of hard spheres. This glass point, “point G", is distinct from athermal jamming thresholds. A remarkable consequence of scaling behaviour is that the dynamics at fixed $\varphi$ passes smoothly from that of a strong glass to that of a very fragile glass as $\varphi$ increases beyond $\varphi_{0}$. Correlations between fragility and various physical properties are explored.

PACS
05.10.-a - Computational methods in statistical physics and nonlinear dynamics.
05.20.Jj - Statistical mechanics of classical fluids.
64.70.P- - Glass transitions of specific systems.

© EPLA 2009