engleski

Kinetic glass behavior in the Edwards-Anderson model with mobile bonds

Two properties of the Edwards-Anderson model with mobile bonds are investigated which are characteristic of kinetic glass simulations. One is the two-temperature violation of the fluctuation-dissipation theorem, which can be tuned by bond dilution in a bimodal bond distribution through the full range of behavior reported in the literature. The limit of no dilution corresponds to the single temperature case, without FDT violation. For a Gaussian bond distribution, the many-temperature behavior is obtained. The other is two-time relaxation in aged systems with a Gaussian bond distribution, where a significant difference is observed between spin and bond autocorrelation functions. The spin subsystem does not show two-time behavior and the relaxation is stretched exponential with b ≈ 0.8. At the same time the bond subsystem shows two-time behavior, with the first (fast) relaxation nearly exponential, and the second (slow) a stretched exponential. Spin relaxation times coincide with the slow bond relaxation times. We conclude that simple Glauber Monte Carlo evolution of the mobile-bond Edwards-Anderson model without extraneous constraints reproduces the behavior of classical kinetic simulations, with the bond (spin) degree of freedom simulating configurational (orientational) disorder.

glass transitions; random models

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