Otherwise identical particles with differing, fixed speeds demix under time-reversible dynamics

BAGLIETTO, G.; SEIF, A.; GRIGERA, T. S.; PAUL, W.

Physical Review E

American Physical Society

Año: 2020 vol. 101 p. 62606 - 62606

2470-0045

In recent years situations where elsewise identical particles demix when different degrees of freedom do notthermalize have become a research focus in nonequilibrium statistical mechanics. The majority of these modelsare formulated in the context of active particles, but the phenomenon also occurs for particles without driving. Allthe models studied so far share the property that they do not obey microscopic reversibility, and it may be thoughtthat this is a necessary condition for such demixing to occur. We show here that such a demixing transition alsooccurs in a mixture of otherwise identical particles moving at two fixed but different speeds according to atime-reversible quasi-Newtonian dynamics. The mechanical instability underlying this behavior is generated bythe lack of thermalization between the two subsystems, which is shared by all systems showing this behavior.