title: Breakdown of scaling in the nonequilibrium critical dynamics of the two-dimensional XY model
abstract: The approach to equilibrium, from a nonequilibrium initial state, in a system at its critical point is usually described by a scaling theory with a single growing length scale, xi(t) approximately t(1/z), where z is the dynamic exponent that governs the equilibrium dynamics. We show that, for the 2D XY model, the rate of approach to equilibrium depends on the initial condition. In particular, xi(t) approximately t(1/2) if no free vortices are present in the initial state, while xi(t) approximately (t/lnt)(1/2) if free vortices are present.
authors.affiliation: Department of Physics and Astronomy, The University, Manchester, M13 9PL, United Kingdom.
authors.initials: AJ
authors.lastname: Bray
authors.initials: AJ
authors.lastname: Briant
authors.initials: DK
authors.lastname: Jervis