Unraveling critical dynamics: The Formation and evolution of topological textures

Nov, 1999
12 pages
Published in:
  • Phys.Rev.D 61 (2000) 085002
e-Print:
Report number:
  • UMD-PP-00-038

Citations per year

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Abstract:
We study the formation of topological textures in a nonequilibrium phase transition of an overdamped classical O(3) model in 2+1 dimensions. The phase transition is triggered through an external, time-dependent effective mass, parameterized by quench timescale \tau. When measured near the end of the transition the texture separation and the texture width scale respectively as \tau^(0.39 \pm 0.02) and \tau^(0.46 \pm 0.04), significantly larger than \tau^(0.25) predicted from the Kibble-Zurek mechanism. We show that Kibble-Zurek scaling is recovered at very early times but that by the end of the transition the power-laws result instead from a competition between the length scale determined at freeze-out and the ordering dynamics of a textured system. In the context of phase ordering these results suggest that the multiple length scales characteristic of the late-time ordering of a textured system derive from the critical dynamics of a single nonequilibrium correlation length. In the context of defect formation these results imply that significant evolution of the defect network can occur before the end of the phase transition. Therefore a quantitative understanding of the defect network at the end of the phase transition generally requires an understanding of both critical dynamics and the interactions among topological defects.
  • texture: topological
  • critical phenomena
  • field theory: scalar
  • symmetry: O(3)
  • dimension: 3
  • astrophysics
  • scaling: violation
  • correlation: length
  • numerical calculations