Huge (but finite) time scales in slow relaxations: beyond simple aging

TL;DR

This paper investigates slow conductance relaxations and aging in porous silicon, revealing universal behavior with a single timescale of thousands of seconds at room temperature, applicable to various glassy systems.

Contribution

The study provides experimental and theoretical evidence of universal aging behavior in conductance relaxation, introducing a model that collapses data onto a single timescale.

Findings

Relaxation timescale of thousands of seconds at room temperature

Universal collapse of experimental data onto a single theoretical curve

Applicability of the method to other glassy systems

Abstract

Experiments performed in the last years demonstrated slow relaxations and aging in the conductance of a large variety of materials. Here, we present experimental and theoretical results for conductance relaxation and aging for the case-study example of porous silicon. The relaxations are experimentally observed even at room temperature over timescales of hours, and when a strong electric field is applied for a time $t_w$, the ensuing relaxation depends on $t_w$. We derive a theoretical curve and show that all experimental data collapse onto it with a single timescale as a fitting parameter. This timescale is found to be of the order of thousands of seconds at room temperature. The generic theory suggested is not fine-tuned to porous silicon, and thus we believe the results should be universal, and the presented method should be applicable for many other systems manifesting memory and other glassy effects.