Matteo Marcuzzi - SISSA Trieste #
<p>Collective non-equilibrium dynamics in the presence of surfaces #
Symmetries can be regarded as non-trivial constraints limiting the 
freedom of a physical system. It has to be expected, therefore, that 
upon relieving some of those restriction will lead to the emergence of 
new phenomena. A fundamental example is provided by space- and 
time-translational invariance in statistical systems, which can be 
thought to eff ectively hold at a coarse-grained scale and can be broken 
by the introduction of boundaries, implemented by surfaces for the 
former (an unavoidable feature in any real sample) and, for the latter, 
by some initial condition for the dynamics which causes a 
non-equilibrium evolution. While the separate e ffects of these two 
boundaries are well understood, additional, unexpected features arise 
upon approaching the eff ective edge formed by their intersection. In 
order to investigate them we have focused on a classical semi-infinite 
Ising model evolving out of equilibrium after a temperature quench from 
the disordered phase to its critical point. Considering both critical 
and tricritical values of the coupling among surface spins, we have 
found numerical evidence of a scaling regime with universal features 
which emerges upon approaching the spatio-temporal edge and we have 
rationalised such  findings within a field-theoretical approach.
</p>
Reference: M. Marcuzzi, A. Gambassi and M. Pleimling, EPL 100, 46004 
(2012)