TY - JOUR

T1 - Controlling the error mechanism in a tunable-barrier nonadiabatic charge pump by dynamic gate compensation

AU - Hohls, Frank

AU - Kashcheyevs, Vyacheslavs

AU - Stein, Friederike

AU - Wenz, Tobias

AU - Kaestner, Bernd

AU - Schumacher, Hans W.

N1 - Funding information: We thank Christoph Leicht and Thomas Weimann for help with the sample fabrication, Holger Marx and Klaus Pierz for providing the GaAs/AlGaAs heterostructure, Martin Götz for the calibration of the ULCAs, and Thomas Gerster for critical reading of the paper. This paper was supported in part by the Joint Research Projects e-SI-Amp (Project No. 15SIB08) and SEQUOIA (Project No. 17FUN04). These projects received funding from the European Metrology Programme for Innovation and Research (EMPIR) cofinanced by the Participating States and from the European Unions Horizon 2020 research and innovation program. H.W.S acknowledges funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy—EXC-2123 QuantumFrontiers No. 390837967. V.K. acknowledges funding by the Latvian Council of Science (Project No. lzp-2018/1-0173). Publisher Copyright: © 2022 American Physical Society.

PY - 2022/5/20

Y1 - 2022/5/20

N2 - Single-electron pumps based on tunable-barrier quantum dots are the most promising candidates for a direct realization of the unit ampere in the recently revised International System of Units (SI): they are simple to operate and show high precision at high operation frequencies. The current understanding of the residual transfer errors at low temperature is based on the evaluation of back-tunneling effects in the decay cascade model. This model predicts a strong dependence on the ratio of the time-dependent changes in the quantum dot energy and the tunneling barrier transparency. Here we employ a two-gate operation scheme to verify this prediction and demonstrate control of the back-tunneling error. We derive and experimentally verify a quantitative prediction for the error suppression, thereby confirming the basic assumptions of the back-tunneling (decay cascade) model. Furthermore, we demonstrate a controlled transition from the back-tunneling dominated regime into the thermal (sudden decoupling) error regime. The suppression of transfer errors by several orders of magnitude at zero magnetic field was additionally verified by a sub-ppm precision measurement.

AB - Single-electron pumps based on tunable-barrier quantum dots are the most promising candidates for a direct realization of the unit ampere in the recently revised International System of Units (SI): they are simple to operate and show high precision at high operation frequencies. The current understanding of the residual transfer errors at low temperature is based on the evaluation of back-tunneling effects in the decay cascade model. This model predicts a strong dependence on the ratio of the time-dependent changes in the quantum dot energy and the tunneling barrier transparency. Here we employ a two-gate operation scheme to verify this prediction and demonstrate control of the back-tunneling error. We derive and experimentally verify a quantitative prediction for the error suppression, thereby confirming the basic assumptions of the back-tunneling (decay cascade) model. Furthermore, we demonstrate a controlled transition from the back-tunneling dominated regime into the thermal (sudden decoupling) error regime. The suppression of transfer errors by several orders of magnitude at zero magnetic field was additionally verified by a sub-ppm precision measurement.

UR - http://www.scopus.com/inward/record.url?scp=85131378968&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.105.205425

DO - 10.1103/PhysRevB.105.205425

M3 - Article

VL - 105

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 20

M1 - 205425

ER -