title: Single-particle fluctuations and directional correlations in driven hard-sphere glasses.
abstract: Via event-driven molecular dynamics simulations and experiments, we study the packing-fraction and shear-rate dependence of single-particle fluctuations and dynamic correlations in hard-sphere glasses under shear. At packing fractions above the glass transition, correlations increase as shear rate decreases: the exponential tail in the distribution of single-particle jumps broadens and dynamic four-point correlations increase. Interestingly, however, upon decreasing the packing fraction, a broadening of the exponential tail is also observed, while dynamic heterogeneity is shown to decrease. An explanation for this behavior is proposed in terms of a competition between shear and thermal fluctuations. Building upon our previous studies [Chikkadi et al., Europhys. Lett. 100, 56001 (2012)], we further address the issue of anisotropy of the dynamic correlations.
authors.affiliation: Max-Planck Institut für Eisenforschung, Max-Planck Strasse 1, 40237 Düsseldorf, Germany.
authors.forename: Suvendu
authors.initials: S
authors.lastname: Mandal
authors.forename: Vijaykumar
authors.initials: V
authors.lastname: Chikkadi
authors.forename: Bernard
authors.initials: B
authors.lastname: Nienhuis
authors.forename: Dierk
authors.initials: D
authors.lastname: Raabe
authors.forename: Peter
authors.initials: P
authors.lastname: Schall
authors.forename: Fathollah
authors.initials: F
authors.lastname: Varnik