History dependence, memory and metastability in electron glasses

TL;DR

This paper investigates how electron glasses exhibit history-dependent conductivity and memory effects, supported by analytical and numerical evidence, revealing the role of local density of states and Coulomb interactions.

Contribution

It introduces a model explaining memory effects in electron glasses through local density of states retention, supported by analytical reasoning and zero-temperature simulations.

Findings

Memory effects saturate with increasing gate voltage change

Local density of states retains sample history

Coulomb glass exhibits short-term incompressibility

Abstract

We discuss the history dependence and memory effects which are observed in the out-of-equilibrium conductivity of electron glasses. The experiments can be understood by assuming that the local density of states retains a memory of the sample history. We provide analytical arguments for the consistency of this assumption, and discuss the saturation of the memory effect with increasing gate voltage change. This picture is bolstered by numerical simulations at zero temperature, which moreover demonstrate the incompressibility of the Coulomb glass on short timescales.