Memory effects in transport through a hopping insulator: Understanding two-dip experiments

TL;DR

This paper investigates how slow electron cluster rearrangements cause memory effects in the conductance of hopping insulators, explaining the dynamics behind two-dip experiments.

Contribution

It introduces a model linking slow many-electron cluster rearrangements to conductance memory effects in hopping insulators, providing a theoretical understanding of two-dip experiments.

Findings

Memory effects arise from slow cluster rearrangements affecting conductance.

The model explains the time-dependent conductance changes observed in experiments.

Rearrangement dynamics are linked to structural defect relaxation processes.

Abstract

We discuss memory effects in the conductance of hopping insulators due to slow rearrangements of many-electron clusters leading to formation of polarons close to the electron hopping sites. An abrupt change in the gate voltage and corresponding shift of the chemical potential change populations of the hopping sites, which then slowly relax due to rearrangements of the clusters. As a result, the density of hopping states becomes time dependent on a scale relevant to rearrangement of the structural defects leading to the excess time dependent conductivity.