Background charge fluctuation in a GaAs quantum dot device

TL;DR

This study examines background charge fluctuations in a GaAs quantum dot device by analyzing 1/f noise in the tunneling current, revealing temperature-dependent potential fluctuations and minor effects from excited state electron injection.

Contribution

It provides a detailed analysis of charge noise sources in GaAs quantum dots and models the temperature dependence of potential fluctuations.

Findings

Potential fluctuation increases linearly with temperature.

Minor increase in fluctuation when electrons occupy excited states.

Noise behavior aligns with a simple 1/f noise model.

Abstract

We investigate background charge fluctuation in a GaAs quantum dot device by measuring 1/f noise in the single-electron tunneling current through the dot. The current noise is understood as fluctuations of the confinement potential and tunneling barriers. The estimated potential fluctuation increases almost linearly with temperature, which is consistent with a simple model of the 1/f noise. We find that the fluctuation increases very slightly when electrons are injected into excited states of the quantum dot.