Evidence for temperature chaos in spin glasses

Abstract

We study the field cooled magnetization of a CuMn spin glass (SG) under temperature perturbations. The $T$-cycling curves are compared with the reference curve without temperature cycling. There is a crossover from the cumulative aging region to noncumulative aging region as the temperature change is increased. The cumulative aging range scales with the chaos length, ${\ensuremath{\ell}}_{\mathrm{c}}$, becoming comparable to the correlation length, $\ensuremath{\xi}$, at the crossover boundary. The extracted chaos exponent, $\ensuremath{\zeta}=1.1$, is in agreement with theoretical predictions. Our results strongly suggest temperature chaos exists in real SG systems.

Topics & Concepts