Aging of amorphous materials under cyclic strain

Dor Shohat; Paul Baconnier; Itamar Procaccia; Martin van Hecke; Yoav Lahini

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arXiv · 2506.08779

Aging of amorphous materials under cyclic strain

Dor Shohat·Paul Baconnier·Itamar Procaccia·Martin van Hecke·Yoav Lahini

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Abstract

Amorphous materials driven away from equilibrium display a diverse repertoire of complex, history-dependent behaviors. One striking feature is a failure to return to equilibrium after an abrupt change in otherwise static external conditions. Instead, amorphous materials often exhibit physical aging: an ever-slowing, nonexponential relaxation that can span a huge range of timescales. Here we examine the aging behavior of three different amorphous materials subjected to slow periodic driving. The results reveal a generic aging phenomenon characterized by a logarithmic decay of dissipation per cycle. This observation is evaluated against several mesoscopic models of amorphous matter that successfully capture aging under static conditions: (i) a collection of noninteracting relaxation processes (ii) a noisy hysteron model with random pairwise interactions, and (iii) a structural model consisting of a random network of bi-stable elastic bonds. We find that only the latter model reproduces all experimental findings and relate its success to its persistent, slow exploration of a complex energy landscape with clear signatures of replica symmetry breaking. Thus, cyclic driving emerges as a simple yet powerful protocol to characterize amorphous materials, probe their complex energy landscapes, and distinguish between different models.

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Dor Shohat, Paul Baconnier, Itamar Procaccia, Martin van Hecke, Yoav Lahini. 2025-06-10. Aging of amorphous materials under cyclic strain. https://arxiv.org/abs/2506.08779

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