Symmetrical Temperature-Chaos Effect with Positive and Negative Temperature Shifts in a Spin Glass

TL;DR

This study investigates aging and rejuvenation in a Heisenberg-like spin glass, revealing that small positive and negative temperature shifts produce equivalent effects on aging, supporting the concept of a unique overlap length in the system.

Contribution

It provides quantitative evidence that positive and negative temperature shifts have symmetrical effects on aging in spin glasses, confirming the existence of a unique overlap length.

Findings

Positive and negative temperature shifts cause equivalent rejuvenation effects.

A crossover from accumulative to non-accumulative aging is observed.

Supports the existence of a unique overlap length in spin glasses.

Abstract

The aging in a Heisenberg-like spin glass Ag(11 at% Mn) is investigated by measurements of the zero field cooled magnetic relaxation at a constant temperature after small temperature shifts $|\Delta T/T_g| < 0.012$. A crossover from fully accumulative to non-accumulative aging is observed, and by converting time scales to length scales using the logarithmic growth law of the droplet model, we find a quantitative evidence that positive and negative temperature shifts cause an equivalent restart of aging (rejuvenation) in terms of dynamical length scales. This result supports the existence of a unique overlap length between a pair of equilibrium states in the spin glass system.