Kinetics of ordering in fluctuation-driven first-order transitions: Simulation and theory

Citation
Na. Gross et al., Kinetics of ordering in fluctuation-driven first-order transitions: Simulation and theory, PHYS REV E, 62(5), 2000, pp. 6116-6125
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW E
ISSN journal
1063-651X → ACNP
Volume
62
Issue
5
Year of publication
2000
Part
A
Pages
6116 - 6125
Database
ISI
SICI code
1063-651X(200011)62:5<6116:KOOIFF>2.0.ZU;2-U
Abstract
Many systems involving competing interactions or interactions that compete with constraints an well described by a model first introduced by Brazovski i [Zh. Eksp. Teer. Fiz. 68, 175 (1975) [Sov. Phys. JETP 41, 85 (1975)]]. Th e hallmark of this model is that the fluctuation spectrum is isotropic and has a maximum at a nonzero wave vector represented by the surface of a d-di mensional hypersphere. It was shown by Brazovskii that the fluctuations cha nge the free energy structure from a phi (4) to a phi (6) form with the dis ordered state metastable for all quench depths. The transition from the dis ordered phase to the periodic lamellar structure changes from second order to first order and suggests that the dynamics is governed by nucleation. Us ing numerical simulations we have confirmed that the equilibrium free energ y function is indeed of a phi (6) form. A study of the dynamics, however, s hows that, following a deep quench, the dynamics is described by unstable g rowth rather than nucleation. A dynamical calculation, based on a generaliz ation of the Brazovskii calculations, shows that the disordered state can r emain unstable for a long time following the quench.