A bacterial ratchet motor (2009)
Di Leonardo, R., Angelani, L., Ruocco, G., Iebba, V., Conte, M. P., Schippa, S., ...
Self-propelling bacteria are a dream of nano-technology. These unicellular organisms are not just capable of living and reproducing, but they can swim very efficiently, sense the environment and look...
Real-time optical manipulation of micron sized structures using GPU generated holograms (2009)
Holographic optical tweezers allow the three dimensional, dynamic, multipoint manipulation of micron sized dielectric objects. Exploiting the massive parallel architecture of modern GPUs we can...
Colloidal attraction induced by a temperature gradient (2008)
Di Leonardo, R., Ianni, F., Ruocco, G.
Colloidal crystals are of extreme importance for applied research, such as photonic crystals technology, and for fundamental studies in statistical mechanics. Long range attractive interactions, such...
Hydrodynamic Interactions in Two Dimensions (2008)
Di Leonardo, R., Keen, S., Ianni, F., Leach, J., Padgett, M., Ruocco, G.
We measure hydrodynamic interactions between colloidal particles confined in a thin sheet of fluid. The reduced dimensionality, compared to a bulk fluid, increases dramatically the range of...
The very long range nature of capillary interactions in liquid films (2007)
Di Leonardo, R., Saglimbeni, F., Ruocco, G.
Micron-sized objects confined in thin liquid films interact through forces mediated by the deformed liquid-air interface. This capillary interactions provide a powerful driving mechanism for the...
Parametric resonance of optically trapped aerosols (2007)
Di Leonardo, R., Ruocco, G., Leach, J., Padgett, M.J., Wright, A.J., Girkin, J.M., ...
The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over- to underdamped oscillations. The spectrum of position fluctuations evolves from a...
Shear banding phenomena in a Laponite suspension (2007)
Ianni, F., Di Leonardo, R., Gentilini, S., Ruocco, G.
Shear localization in an aqueous clay suspension of Laponite is investigated through dynamic light scattering, which provides access both to the dynamics of the system (homodyne mode) and to the...
Parametric Resonance of Optically Trapped Aerosols (2007)
Di Leonardo, R., Ruocco, G., Leach, J., Padgett, M. J., Wright, A. J., Girkin, J. M., ...
The Brownian dynamics of an optically trapped water droplet are investigated across the transition from over to under-damped oscillations. The spectrum of position fluctuations evolves from a...
Ianni, F., Di Leonardo, R., Gentilini, S., Ruocco, G.
The aging dynamics after shear rejuvenation in a glassy, charged clay suspension have been investigated through dynamic light scattering (DLS). Two different aging regimes are observed: one is...
Hard sphere-like dynamics in a non hard sphere liquid (2005)
Scopigno, T., Di Leonardo, R., Comez, L., Baron, A. Q. R., Fioretto, D., Ruocco, G.
The collective dynamics of liquid Gallium close to the melting point has been studied using Inelastic X-ray Scattering to probe lengthscales smaller than the size of the first coordination shell....
Aging under Shear: Structural Relaxation of a Non-Newtonian Fluid (2004)
Di Leonardo, R., Ianni, F., Ruocco, G.
The influence of an applied shear field on the dynamics of an aging colloidal suspension has been investigated by the dynamic light scattering determination of the density autocorrelation function....
High frequency dynamics in a monatomic glass (2003)
Scopigno, T., Di Leonardo, R., Ruocco, G., Baron, A. Q. R., Tsutsui, S., Bossard, F., ...
The high frequency dynamics of glassy Selenium has been studied by Inelastic X-ray Scattering at beamline BL35XU (SPring-8). The high quality of the data allows one to pinpoint the existence of a...
A spectroscopic cell for fast pressure jumps across the glass transition line (2003)
Di Leonardo, R., Scopigno, T., Ruocco, G., Buontempo, U.
We present a new experimental protocol for the spectroscopic study of the dynamics of glasses in the aging regime induced by sudden pressure jumps (crunches) across the glass transition line. The...
Di Leonardo, R., Taschin, A., Sampoli, M., Torre, R., Ruocco, G.
The density response of supercooled glycerol to an impulsive stimulated thermal grating (q=0.63 micron^-1) has been studied in the temperature range (T=200-340 K) where the structure rearrangement...
Experimental evidence for high frequency transverse-like excitations in glasses (2002)
Scopigno, T., Pontecorvo, E., Di Leonardo, R., Krisch, M., Monaco, G., Ruocco, G., ...
The dynamic structure factor of glassy and liquid glycerol has been measured by inelastic X-ray scattering in the exchanged momentum ($Q$) region $Q$=2$\div$23 nm$^{-1}$ and in the temperature range...
Angelani, L., Di Leonardo, R., Ruocco, G., Scala, A., Sciortino, F.
The supercooled dynamics of a Lennard-Jones model liquid is numerically investigated studying relevant points of the potential energy surface, i.e. the minima of the square gradient of total...
Off-equilibrium dynamics in the energy landscape of a simple model glass (2001)
Di Leonardo, R., Angelani, L., Parisi, G., Ruocco, G., Scala, A., Sciortino, F.
The aging dynamics of a simple model glass is numerically investigated observing how it takes place in the potential energy landscape $V$. Partitioning the landscape in basins of minima of $|\nabla...
A stroll in the energy landscape (2001)
Scala, A., Angelani, L., Di Leonardo, R., Ruocco, G., Sciortino, F.
We review recent results on the potential energy landscape (PES) of model liquids. The role of saddle-points in the PES in connecting dynamics to statics is investigated, confirming that a change...
Topological Description of the Aging Dynamics in Simple Glasses (2000)
Angelani, L., Di Leonardo, R., Parisi, G., Ruocco, G.
We numerically investigate the aging dynamics of a monatomic Lennard-Jones glass, focusing on the topology of the potential energy landscape which, to this aim, has been partitioned in basins of...
Monaco, G., Caponi, S., Di Leonardo, R., Fioretto, D., Ruocco, G.
The Brillouin light scattering spectra of the o-terphenyl single crystal are compared with those of the liquid and the glass phases. This shows: i) the direct evidence of a fast relaxation at 5 GHz...
Saddles in the energy landscape probed by supercooled liquids (2000)
Angelani, L., Di Leonardo, R., Ruocco, G., Scala, A., Sciortino, F.
We numerically investigate the supercooled dynamics of two simple model liquids exploiting the partition of the multi-dimension configuration space in basins of attraction of the stationary points...
Off-Equilibrium Effective Temperature in Monatomic Lennard-Jones Glass (2000)
Di Leonardo, R., Angelani, L., Parisi, G., Ruocco, G.
The off-equilibrium dynamics of a monatomic Lennard-Jones glass is investigated after sudden isothermal density jumps (crunch) from well equilibrated liquid configurations towards the glassy state....
Relaxation processes in harmonic glasses? (2000)
Ruocco, G., Sette, F., Di Leonardo, R., Monaco, G., Sampoli, M., Scopigno, T., ...
A relaxation process, with the associated phenomenology of sound attenuation and sound velocity dispersion, is found in a simulated harmonic Lennard-Jones glass. We propose to identify this process...
Mossa, S., Di Leonardo, R., Ruocco, G., Sampoli, M.
We present a realistic model of the fragile glass former orthoterphenyl and the results of extensive molecular dynamics simulations in which we investigated its basic static and dynamic properties....
Non-dynamic origin of the acoustic attenuation at high frequency in glasses (1999)
Ruocco, G., Sette, F., Di Leonardo, R., Fioretto, D., Lorenzen, M., Krisch, M., ...
The sound attenuation in the THz region is studied down to T=16 K in glassy glycerol by inelastic x-ray scattering. At striking variance with the decrease found below 100 K in the GHz data, the...
Montagna, M., Ruocco, G., Viliani, G., Di Leonardo, R., Dusi, R., Monaco, G., ...
We propose an explanation for the quadratic dependence on the momentum $Q$, of the broadening of the acoustic excitation peak recently found in the study of the dynamic structure factor of many real...