Charge filling factors in clean and disordered arrays of tunnel junctions

TL;DR

This study uses kinetic Monte Carlo simulations to analyze charge filling factors in one-dimensional tunnel junction arrays, revealing how background charge disorder influences observable fractional charge states.

Contribution

It provides new insights into how background charge disorder affects charge filling factors in tunnel junction arrays, especially under different disorder strengths.

Findings

Small fractional charge filling factors are likely obscured by strong disorder.

Larger filling factors may still be observable despite disorder effects.

Charge filling behavior is highly sensitive to background charge disorder.

Abstract

We simulate one-dimensional arrays of tunnel junctions using the kinetic Monte Carlo method to study charge filling behaviour in the large charging energy limit. By applying a small fixed voltage bias and varying the offset voltage, we investigate this behaviour in clean and disordered arrays (both weak and strong disorder effects). The offset voltage dependent modulation of the current is highly sensitive to background charge disorder and exhibits substantial variation depending on the strength of the disorder. We show that while small fractional charge filling factors are likely to be washed out in experimental devices due to strong background charge disorder, larger factors may be observable.