Towards an experimental measure of the number of metastable states in spin-glasses ?

TL;DR

This paper introduces a method to measure the number of metastable states in spin-glasses using aging experiments, revealing a vast number of such states and their temperature dependence in different materials.

Contribution

It proposes an ergodic time scale from aging experiments to estimate the number of metastable states in spin-glasses, providing experimental insights into their complexity.

Findings

Number of metastable states per subsystem is approximately 10^{12}-10^{14}.

The metastable state count doubles with a 1K temperature decrease in insulating spin-glass.

The metastable state count remains roughly constant in the metallic spin-glass.

Abstract

We show that an 'ergodic' time scale can be extracted from the aging experiments on spin-glasses. This is the time for which a significant fraction of the metastable states have been visited. Experiments suggest that the number of metastable states per independent subsystem is $\simeq 10^{12}-10^{14}$. For our insulating spin-glass $({\rm CdCr}_{1.7} {\rm In}_{0.3} {\rm S}_4)$ this number doubles when the temperature is lowered by 1K, but is roughly constant for the metallic sample (Ag:Mn 2.6%).