Observable Dependent Quasi-Equilibrium in Slow Dynamics

Abstract

We present examples demonstrating that quasi-equilibrium fluctuation-dissipation behavior at short time differences is not a generic feature of systems with slow non-equilibrium dynamics. We analyze in detail the non-equilibrium fluctuation-dissipation ratio X(t,tw) associated with a defect-pair observable in the Glauber-Ising spin chain. It turns out that $X\ne 1$ throughout the short-time regime and in particular X(tw,tw) = 3/4 for $tw\to \infty$. The analysis is extended to observables detecting defects at a finite distance from each other, where similar violations of quasi-equilibrium behaviour are found. We discuss our results in the context of metastable states, which suggests that a violation of short-time quasi-equilibrium behavior could occur in general glassy systems for appropriately chosen observables.

17 pages, 5 figures; substantially improved version of cond-mat/0405711

References in corpus (5)

• Glassy dynamics of kinetically constrained models
• Fluctuation-dissipation relations in the non-equilibrium critical dynamics of Ising models
• Bona Fide Thermodynamic Temperature in Nonequilibrium Kinetic Ising Models
• General Solutions for Multispin Two-Time Correlation and Response Functions in the Glauber-Ising Chain
• Reply to Comment on "Fluctuation-dissipation relations in the non-equilibrium critical dynamics of Ising models"