Aging rate of spin glasses from simulations matches experiments

TL;DR

This paper uses advanced simulations to reconcile differences between experimental and numerical measurements of the aging rate exponent in spin glasses, providing a unified understanding of their growth dynamics.

Contribution

The study introduces a time-dependent exponent $z(T, t_w)$ and demonstrates its connection to experimental values through extrapolation, also exploring the crossover between fixed points.

Findings

Simulation results match experimental aging exponents after extrapolation.

Identification of a crossover between $T_c$ and $T=0$ fixed points.

Resolution of previous discrepancies between experiments and simulations.

Abstract

Experiments on spin glasses can now make precise measurements of the exponent $z(T)$ governing the growth of glassy domains, while our computational capabilities allow us to make quantitative predictions for experimental scales. However, experimental and numerical values for $z(T)$ have differed. We use new simulations on the Janus II computer to resolve this discrepancy, finding a time-dependent $z(T, t_w)$, which leads to the experimental value through mild extrapolations. Furthermore, theoretical insight is gained by studying a crossover between the $T = T_c$ and $T = 0$ fixed points.