https://doi.org/10.1140/epjst/e2010-01315-y
Regular Article
Molecular dynamics studies of slow dynamics in random media: Type A-B and reentrant transitions
1 Institute for Molecular Science, Okazaki 444-8585, Japan
2 The Graduate University for Advanced Studies, Okazaki 444-8585, Japan
3 Institute of Physics, University of Tsukuba, Tsukuba 305-8571, Japan
a e-mail: kin@ims.ac.jp
Received:
1
September
2010
Revised:
14
September
2010
Published online:
12
November
2010
Molecular dynamics simulations of mobile particles confined in disordered immobile particles are carried out. Slow dynamics in random media are characterized by two types of dynamics: Type B dynamics for large mobile particle density and Type A dynamics for small mobile particle density. The crossover from Type A to B dynamics is studied by the mean square displacement and the density correlation function. Our results are qualitatively consistent with the results of recent numerical and theoretical studies on relevant spatially heterogeneous systems. We also investigate the effect of random matrix generation on the dynamics of mobile particles in order to examine the reentrant transition predicted by the recent mode-coupling theory. Our simulations demonstrate that the diffusion of the mobile particles largely depends on the protocol of the random matrix generation and that the reentrant transition is observed for a particular protocol.
© EDP Sciences, Springer-Verlag, 2010