2016/08/31 by Yoav Lahini, Omer Gottesman, Ariel Amir +1 · 1 citation
Physics and Astronomy · #cond-mat.soft #cond-mat.dis-nn
paper · pdf · doi:10.1103/physrevlett.118.085501
published as Phys. Rev. Lett. 118, 085501 (2017) · 5 pages, 5 figures
arxiv created 2017/04/13 · arxiv updated 2017/04/14
We observe non-monotonic aging and memory effects, two hallmarks of glassy dynamics, in two disordered mechanical systems: crumpled thin sheets and elastic foams. Under fixed compression, both systems exhibit monotonic non-exponential relaxation. However, when after a certain waiting time the compression is partially reduced, both systems exhibit a non-monotonic response: the normal force first increases over many minutes or even hours until reaching a peak value, and only then relaxation is resumed. The peak-time scales linearly with the waiting time, indicating that these systems retain long-lasting memory of previous conditions. Our results and the measured scaling relations are in good agreement with a theoretical model recently used to describe observations of monotonic aging in several glassy systems, suggesting that the non-monotonic behavior may be generic and that a-thermal systems can show genuine glassy behavior.