Attractive glasses simulations

A trend in modern MD (and MC) simulations is to enhance system equilibration at low temperatures by the use of novel parallel techniques. One such technique which has recently attracted considerable attention in different variations is parallel tempering (PT) [47,48]. PT was introduced in the context of spin glass simulations, but the real efficiency of the method was demonstrated in a variety of cases, such as in the study of the conformational properties of complex biological molecules [49,50]. Sugita... 

Eigure 13.13 A sketch of state diagram of a colloid-polymer mixture redrawn from Zaccarelli and Poon (2009). Their simulations show that four distinct states exist ergodic fluid nonbonded repulsive glass (hard-sphere glass), bonded repulsive glass (attractive glass) and dense gel. 

FIGURE 7.18 MCT analysis of fluid states close to the attractive glass. With the structure factor from simulations of the system, the nonergodicity parameter (left panel) and time scale (right panel) from the von Schweidler analysis are compared with the theoretical calculations (continuous lines). The structure factors are included in the left panel, to be read in the right scale. (A) Monodisperse system without the repulsive barrier, (B) with the barrier, and (C) polydisperse. The nonergodicity parameter for HS is also included for comparison. (From Henrich O. et al. 2007. Phys. Rev. E 76 031404. With permission.)... 

Finally, several routes to gelation have been presented systems with arrested spinodal decomposition and without states of fluid-fluid coexistence, systems where the fluid-fluid separation is arrested only at very low temperatures (but can be observed at higher ones), and systems where the fluid-fluid transition is suppressed. Whereas the former probably applies to most experiments with short-range attractions (colloid-polymer mixtures), the second mechanism is found when longer-ranged attractions are present (particularly in the case of proteins). The latter has been extensively studied by computer simulations since it allows access to the attractive glass transition from homogeneous fluid states and is the main objective of the present work. 

Magnetic resonance in an assembly of ferromagnetic nanoparticles in ferrofluids, glasses and other systems has attracted much attention. But, up to now, only a few attempts have been made of quantitative, computer-simulation based analysis of SPR spectra of magnetic nanoparticles dispersed in glassy systems [2-11]. 

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