Nonexponential Relaxations in a Two-Dimensional Electron System in Silicon

TL;DR

This study investigates nonexponential conductivity relaxations in a disordered 2D silicon electron system, revealing evidence of a glassy phase transition at low temperatures and emphasizing the role of Coulomb interactions in out-of-equilibrium dynamics.

Contribution

It provides new insights into the relaxation behavior of 2D electron systems, highlighting the transition to a glassy phase and the significance of Coulomb interactions.

Findings

Relaxation dynamics depend strongly on carrier density and temperature.

Evidence suggests a transition to a glassy phase as temperature approaches zero.

Coulomb interactions dominate the out-of-equilibrium behavior.

Abstract

The relaxations of conductivity have been studied in a strongly disordered two-dimensional (2D) electron system in Si after excitation far from equilibrium by a rapid change of carrier density n_s at low temperatures T. The dramatic and precise dependence of the relaxations on n_s and T strongly suggests (a) the transition to a glassy phase as T->0, and (b) the Coulomb interactions between 2D electrons play a dominant role in the observed out-of-equilibrium dynamics.