Three-waveform bidirectional pumping of single electrons with a silicon quantum dot

TL;DR

This paper presents a silicon quantum dot single-electron pump with a three-waveform RF control that enables robust bidirectional electron pumping, potentially advancing quantum current standards and error counting in quantum metrology.

Contribution

It introduces a novel three-waveform control protocol for silicon quantum dot pumps, enhancing robustness and enabling bidirectional electron transfer with simple phase adjustments.

Findings

Bidirectional pumping achieved by phase shift control.

Improved robustness with three control voltages.

Potential application in error counting experiments.

Abstract

Semiconductor-based quantum dot single-electron pumps are currently the most promising candidates for the direct realization of the emerging quantum standard of the ampere in the International System of Units. Here, we discuss a silicon quantum dot single-electron pump with radio frequency control over the transparencies of entrance and exit barriers as well as the dot potential. We show that our driving protocol leads to robust bidirectional pumping: one can conveniently reverse the direction of the quantized current by changing only the phase shift of one driving waveform with respect to the others. We also study the improvement in the robustness of the current quantization owing to the introduction of three control voltages in comparison with the two-waveform driving. We anticipate that this pumping technique may be used in the future to perform error counting experiments by pumping the electrons into and out of a reservoir island monitored by a charge sensor.