Ambipolar quantum dots in intrinsic silicon

TL;DR

This paper reports on the electrical measurement of ambipolar quantum dots in intrinsic silicon, enabling the study of both electron and hole transport regimes within a single device, revealing differences in charge localization and noise.

Contribution

It demonstrates the fabrication and analysis of ambipolar quantum dots in silicon, allowing direct comparison of electron and hole transport in the same device.

Findings

Greater charge localization under tunnel barriers for holes

Higher charge noise in the p-regime

Both transport regimes can be studied in a single device

Abstract

We electrically measure intrinsic silicon quantum dots with electrostatically defined tunnel barriers. The presence of both p-type and n-type ohmic contacts enables the accumulation of either electrons or holes. Thus we are able to study both transport regimes within the same device. We investigate the effect of the tunnel barriers and the electrostatically defined quantum dots. There is greater localisation of charge states under the tunnel barriers in the case of hole conduction leading to higher charge noise in the p-regime.