Quantifying memory in spin glasses

TL;DR

This paper introduces and compares quantitative coefficients for measuring memory effects in spin glasses, combining simulations and experiments to establish their physical equivalence and dependence on temperature and waiting time.

Contribution

It presents a unified framework for quantifying memory in spin glasses using multiple coefficients and demonstrates their physical equivalence through combined numerical and experimental analysis.

Findings

Coefficients for memory are physically equivalent.

Memory effects depend on temperature and waiting time.

Simulations and experiments align in quantifying spin glass memory.

Abstract

Rejuvenation and memory, long considered the distinguishing features of spin glasses, have recently been proven to result from the growth of multiple length scales. This insight, enabled by simulations on the Janus~II supercomputer, has opened the door to a quantitative analysis. We combine numerical simulations with comparable experiments to introduce two coefficients that quantify memory. A third coefficient has been recently presented by Freedberg et al. We show that these coefficients are physically equivalent by studying their temperature and waiting-time dependence.