Issue
EPL
Volume 77, Number 5, March 2007
Article Number 50008
Number of page(s) 5
Section General
DOI http://dx.doi.org/10.1209/0295-5075/77/50008
Published online 27 February 2007
EPL, 77 (2007) 50008
DOI: 10.1209/0295-5075/77/50008

A theory for critically divergent fluctuations of dynamical events at non-ergodic transitions

M. Iwata and S. Sasa

Department of Pure and Applied Sciences, University of Tokyo - Komaba, Tokyo 153-8902, Japan


received 14 September 2006; accepted in final form 22 January 2007; published March 2007
published online 27 February 2007

Abstract
We theoretically study divergent fluctuations of dynamical events at non-ergodic transitions. We first focus on the finding that a non-ergodic transition can be described as a saddle connection bifurcation of an order parameter for a time correlation function. Then, following the basic idea of Ginzburg-Landau theory for critical phenomena, we construct a phenomenological framework with which we can determine the critical statistical properties at saddle connection bifurcation points. Employing this framework, we analyze a model by considering the fluctuations of an instanton in space-time configurations of the order parameter. We then obtain the exponents characterizing the divergences of the length scale, the time scale and the amplitude of the fluctuations of the order parameter at the saddle connection bifurcation. The results are to be compared with those of previous studies of the four-point dynamic susceptibility at non-ergodic transitions in glassy systems.

PACS
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
02.50.-r - Probability theory, stochastic processes, and statistics.
64.70.Pf - Glass transitions.

© Europhysics Letters Association 2007