Ballistic displacements within string-like motions in a supercooled liquid

G.A. APPIGNANESI, M.A. FRECHERO, L.M. ALARCÓN, J.A. RODRÍGUEZ FRIS Y R.A. MONTANI

PHYSICA A - STATISTICAL AND THEORETICAL PHYSICS

Elsevier

Año: 2004 vol. 339 p. 469 - 481

0378-4371

We perform a series of molecular dynamics simulations in a binary Lennard-Jones system at temperatures close to its mode-coupling temperature, Tc. We demonstrate that the string-like movements carried out by a fraction of the particles are of ballistic nature. Depending on temperature these ballistic strings are found to become rare events related to free-volume effects on the sample. These facts point to a mechanistic description of the transport process and enables us to provide a microscopic reason for the occurrence of timescale separation.