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

Tuomo Tanttu,Mikko Möttönen,Alessandro Rossi,Kuan Yen Tan,Akseli Mäkinen,Andrew S Dzurak,Kok Wai Chan

doi:10.1038/srep36381

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 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.

Highlights

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
After a quarter of a century of development of charge pumps, we are close to redefining the International System of Units (SI) standard for the electrical current, the ampere, such that it would be based on a fixed value of the elementary charge[1,2]
We pump with sinusoidal radio frequency waveforms applied to the plunger gate (PL) and to the barrier right gate (BR) with a phase difference of PL with respect to BR, φBR-PL = 95° at 800 mK temperature

Summary

Introduction

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. 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 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. Our technology allows simultaneous control over both barriers and the dot potential, enabling convenient switching between the www.nature.com/scientificreports/

Methods

Results

Conclusion