H. George E. Hentschel, Itamar Procaccia, Jacques Zylberg
Generic glass formers exhibit at least two characteristic changes in their
relaxation behavior, first to an Arrhenius-type relaxation at some
characteristic temperature, and then at a lower characteristic temperature to a
super-Arrhenius (fragile) behavior. We address these transitions by studying
the statistics of free energy barriers for different systems at different
temperatures and space dimensions. We present a clear evidence for changes in
the dynamical behavior at the transition to Arrhenius and then to a
super-Arrhenius behavior. A simple model is presented, based on the idea of
competition between single-particle and cooperative dynamics. We show that this
model captures all the qualitative behavior observed in simulations throughout
the considered temperature range.
View original:
http://arxiv.org/abs/1202.1127
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