title: Cage Size and Jump Precursors in Glass-Forming Liquids: Experiment and Simulations.
abstract: Glassy dynamics is intermittent, as particles suddenly jump out of the cage formed by their neighbors, and heterogeneous, as these jumps are not uniformly distributed across the system. Relating these features of the dynamics to the diverse local environments explored by the particles is essential to rationalize the relaxation process. Here we investigate this issue characterizing the local environment of a particle with the amplitude of its short time vibrational motion, as determined by segmenting in cages and jumps the particle trajectories. Both simulations of supercooled liquids and experiments on colloidal suspensions show that particles in large cages are likely to jump after a small time-lag, and that, on average, the cage enlarges shortly before the particle jumps. At large time-lags, the cage has essentially a constant size, which is smaller for longer-lasting cages. Finally, we clarify how this coupling between cage size and duration controls the average behavior and opens the way to a better understanding of the relaxation process in glass-forming liquids.
authors.affiliation: CNR-SPIN, sezione di Napoli, Dipartimento di Fisica, Campus universitario di Monte S. Angelo, Via Cintia, 80126 Napoli, Italy.
authors.forename: Raffaele
authors.identifier: http://orcid.org/0000-0002-8335-9961
authors.initials: R
authors.lastname: Pastore
authors.affiliation: Dipartimento di Fisica, Universitá di Napoli Federico II, Campus universitario di Monte S. Angelo, Via Cintia, 80126 Napoli, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pesce
authors.affiliation: Dipartimento di Fisica, Universitá di Napoli Federico II, Campus universitario di Monte S. Angelo, Via Cintia, 80126 Napoli, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Sasso
authors.affiliation: CNR-SPIN, sezione di Napoli, Dipartimento di Fisica, Campus universitario di Monte S. Angelo, Via Cintia, 80126 Napoli, Italy.|Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore , 639798.
authors.forename: Massimo
authors.initials: M
authors.lastname: Pica Ciamarra