Single-electron shuttle based on a silicon quantum dot

TL;DR

This paper demonstrates controlled single-electron shuttling in a silicon quantum dot at high frequencies, achieving current quantization and analyzing the effects of ac driving on electron heating.

Contribution

It introduces a silicon-based quantum dot system capable of high-frequency single-electron shuttling with observed quantized current plateaus up to 240 MHz.

Findings

Current plateaus at integer ef_p levels up to 240 MHz

Sequential tunneling model explains electron heating effects

Potential for high-frequency quantum electron transport

Abstract

We report on single-electron shuttling experiments with a silicon metal-oxide-semiconductor quantum dot at 300 mK. Our system consists of an accumulated electron layer at the Si/SiO_2 interface below an aluminum top gate with two additional barrier gates used to deplete the electron gas locally and to define a quantum dot. Directional single-electron shuttling from the source and to the drain lead is achieved by applying a dc source-drain bias while driving the barrier gates with an ac voltage of frequency f_p. Current plateaus at integer levels of ef_p are observed up to f_p = 240 MHz operation frequencies. The observed results are explained by a sequential tunneling model which suggests that the electron gas may be heated substantially by the ac driving voltage.