QuantumFrontiers Success Stories: Electrical quantum metrology – QuantumFrontiers

Significantly reduced measurement uncertainty

Lowering the relative uncertainty beyond the present value of 9.2 ×10^–7 [1] requires validated quantised current sources with heavily scaled-up output currents, a key focus of QuantumFrontiers activities. Scientist from the national metrology institute PTB, TU Braunschweig, and Leibniz University made significant progress, laying the groundwork for future quantum metrology triangle with greatly reduced uncertainty. They validated the universality of the tunnelling dynamics of advanced single electron pumps [2] through single charge detection [3, 4] and also developed the first superconducting quantum current source based on synchronised Bloch oscillations [5], enabling significantly higher quantised currents.

The quantum metrological triangle experiment tests the mutual consistency of the quantisation of the Josephson effect, the quantum Hall effect, and of a quantum current source in a single experiment.

Successful transfer to other scientific fields

The team conducted the most thorough universality test of the quantum Hall effect, achieving unmatched precision in measuring the Hall quantisation of electrons, holes, Dirac fermions, and edge states of topological insulators with an uncertainty of a few parts in 10^–9 [6]. These results were based on high-quality quantum materials developed within the first funding period of QuantumFrontiers, ranging from epitaxial graphene [7] to high-temperature superconductors [8]. The concepts, materials, and devices of electrical quantum metrology were successfully transferred to other scientific fields. For example, SEPs and detectors were used in a Hong-Ou-Mandel type electron quantum optics collision experiment with on-demand fermions [9]. Portable Josephson standards stabilised Penning traps [10] and precisely measured particle accelerator magnet currents at CERN’s high luminosity Large Hadron Collider (LHC) [11].

This article is part of a series on QuantumFrontiers success stories

High-temperature superconductors enabled THz microscopy [8], and high-quality epitaxial graphene allowed the observation of Floquet states [12]. Additionally, the concept of a gravitational metrological triangle was proposed as a quantum test of the Weak Equivalence Principle [13]. These achievements highlight the broad impact of QuantumFrontiers on science and technology beyond electrical metrology.

Topical Groups involved

Topological Systems

Publications

Bibliography

[1] M. W. Keller, A. L. Eichenberger, J. M. Martinis, N. M. Zimmerman. A Capacitance Standard Based on Counting Electrons.
Science 285, 1706–1709. doi:10.1126/science.285.5434.1706 (1999).

[2] F. Hohls, V. Kashcheyevs, et int, H. W. Schumacher. Controlling the error mechanism in a tunable-barrier nonadiabatic charge pump by dynamic gate compensation.
Physical Review B 105. doi:10.1103/physrevb.105.205425 (2022).

[3] D. Reifert, M. Kokainis, et int, N. Ubbelohde. A random-walk benchmark for single-electron circuits.
Nature Communications 12. doi:10.1038/s41467-020-20554-w (2021).

[4] F. Brange, A. Schmidt, et int, R. J. Haug. Controlled emission time statistics of a dynamic single-electron transistor.
Science Advances 7. doi:10.1126/sciadv.abe0793 (2021).

[5] F. Kaap, C. Kissling, et int, S. Lotkhov. Demonstration of dual Shapiro steps in small Josephson junctions.
arXiv: 2401.06599 [cond-mat.mes-hall] (2024).

[6] Y. Yin, M. Kruskopf, et int, H. W. Schumacher. Quantum Hall resistance standards based on epitaxial graphene with p-type conductivity.
Applied Physics Letters 125. doi:10.1063/5.0223723 (2024).

[7] D. Momeni Pakdehi, P. Schädlich, et int, H. W. Schumacher. Silicon Carbide Stacking-Order-Induced Doping Variation in Epitaxial Graphene.
Advanced Functional Materials 30. doi:10.1002/adfm.202004695 (2020).

[8] P. J. Ritter, F.-N. Stapelfeldt, et int, B. Hampel. Antenna Designs for Efficient Coupling to Josephson Junctions for THz Microscopy.
IEEE Transactions on Applied Superconductivity 33, 1–5. doi:10.1109/tasc.2023.3249132 (2023).

[9] N. Ubbelohde, L. Freise, et int, V. Kashcheyevs. Two electrons interacting at a mesoscopic beam splitter.
Nature Nanotechnology 18, 733–740. doi:10.1038/s41565-023-01370-x (2023).

[10] A. Kaiser, S. Dickopf, et int, K. Blaum. Josephson voltage standards as ultra-stable low-noise voltage sources for precision Penning-trap experiments.
Applied Physics Letters 124. doi:10.1063/5.0206779 (2024).

[11] N. Beev, M. C. Bastos, et int, R. Behr. Design and Metrological Characterization of a Digitizer for the Highest Precision Magnet Powering in the High Luminosity Large Hadron Collider.
IEEE Transactions on Instrumentation and Measurement 73, 1–10. doi:10.1109/tim.2023.3343809 (2024).

[12] M. Merboldt, M. Schüler, et int, S. Mathias. Observation of Floquet states in graphene.
arXiv: 2404.12791 [cond-mat.mes-hall] (2024).

[13] C. Lammerzahl, S. Ulbricht. A gravitational metrological triangle.
arXiv: 2402.04135 [gr-qc] (2024).

Success Story: Electrical quantum metrology

Significantly reduced measurement uncertainty

Successful transfer to other scientific fields

This article is part of a series on QuantumFrontiers success stories

Topical Groups involved

Publications