Aging and memory in a two-dimensional electron system in Si

TL;DR

This study investigates aging and memory effects in the conductivity of a disordered two-dimensional silicon electron system, revealing complex non-equilibrium dynamics and a transition in behavior at the metal-insulator critical density.

Contribution

It provides new insights into the non-equilibrium relaxation dynamics and aging phenomena in 2D electron systems near the metal-insulator transition in silicon.

Findings

Aging and memory effects are observed below a certain carrier density.

Relaxation dynamics change abruptly at the critical density for the metal-insulator transition.

Electronic transport exhibits complex, nonexponential relaxation similar to other far-from-equilibrium systems.

Abstract

The relaxations of conductivity after a temporary change of carrier density n_s during the waiting time t_w have been studied in a strongly disordered two-dimensional electron system in Si. At low enough n_s < n_g (n_g - the glass transition density), the nonexponential relaxations exhibit aging and memory effects at low temperatures T. The aging properties change abruptly at the critical density for the metal-insulator transition n_c < n_g. The observed complex dynamics of the electronic transport is strikingly similar to that of other systems that are far from equilibrium.