Robust formation of quantum dots in GaAs/AlGaAs heterostructures for single-electron metrology

Gerster, Thomas; Müller, A.; Freise, L.; Reifert, David; Maradan, Dario; Hinze, P.; Weimann, Thomas; Marx, H; Pierz, K.; Schumacher, H. W.; Hohls, Frank; Ubbelohde, Niels

doi:10.1088/1681-7575/aaf4aa

Cited by 11 publications

(7 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the same time, these complex properties are precisely the reason for its robustness and appeal for practical applications. It is nowadays at the heart of the definition of the electrical metrological standards [5], while it is also a promising platform for the development of topological quantum computation [6].…”

Section: Introductionmentioning

confidence: 99%

Thermoelectricity in Quantum Hall Corbino Structures

et al. 2020

View full text Add to dashboard Cite

We measure the thermoelectric response of Corbino structures in the quantum Hall effect regime and compare it with a theoretical analysis. The measured thermoelectric voltages are qualitatively and quantitatively simulated based upon the independent measurement of the conductivity, indicating that they originate predominantly from the electron diffusion. In contrast to earlier Hall-bar experiments, electronphonon interaction does not lead to a phonon-drag contribution. This implies a description of the Onsager coefficients on the basis of a single transmission function, from which both thermovoltage and conductivity can be predicted with a single fitting parameter. Furthermore, it lets us predict a figure of merit for the efficiency of thermoelectric cooling, which becomes very large for partially filled Landau levels and high magnetic fields.

show abstract

Section: Introductionmentioning

confidence: 99%

Thermoelectricity in Quantum Hall Corbino Structures

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The working points of the pumps are not retuned when operating the full circuit. Reproducible formation of quantum dots 30 allows demonstrating the high-fidelity operation of the circuit event at zero magnetic field, at which readout precision is enhanced by cryogenic reflectometry.…”

Section: Resultsmentioning

confidence: 99%

“…Devices A and B were fabricated from GaAs/AlGaAs heterostructures with two dimensional electron gas (2DEG) nominally 90 nm below the surface. Quantum dots are formed by CrAu top gates depleting a shallow-etched mesa 30 . The charge detector is formed against the edge of a separate mesa and capacitively coupled to the central quantum dot via a floating gate 45 .…”

Section: Methodsmentioning

confidence: 99%

A random-walk benchmark for single-electron circuits

et al. 2021

View full text Add to dashboard Cite

Mesoscopic integrated circuits aim for precise control over elementary quantum systems. However, as fidelities improve, the increasingly rare errors and component crosstalk pose a challenge for validating error models and quantifying accuracy of circuit performance. Here we propose and implement a circuit-level benchmark that models fidelity as a random walk of an error syndrome, detected by an accumulating probe. Additionally, contributions of correlated noise, induced environmentally or by memory, are revealed as limits of achievable fidelity by statistical consistency analysis of the full distribution of error counts. Applying this methodology to a high-fidelity implementation of on-demand transfer of electrons in quantum dots we are able to utilize the high precision of charge counting to robustly estimate the error rate of the full circuit and its variability due to noise in the environment. As the clock frequency of the circuit is increased, the random walk reveals a memory effect. This benchmark contributes towards a rigorous metrology of quantum circuits.

show abstract

“…Devices A and B were fabricated from GaAs/AlGaAs heterostructures with two dimensional electron gas (2DEG) nominally 90 nm below the surface. Quantum dots are formed by CrAu top gates depleting a shallowetched mesa [37]. The charge detector is formed against the edge of a separate mesa and capacitively coupled to the central quantum dot via a floating gate [38].…”

Section: Methodsmentioning

confidence: 99%

A random-walk benchmark for single-electron circuits

Reifert,

Kokainis,

Ambainis

et al. 2020

Preprint

View full text Add to dashboard Cite

Mesoscopic integrated circuits achieving high-fidelity control of elementary quantum systems require new methodology for benchmarking. We offer circuit-level statistical description of rare-error accumulation in terms of a universal random-walk model for on-demand electron transfer. For a high-fidelity single-electron circuit, realized in the experiment as a chain of quantum dots in a GaAs/AlGaAs heterostructure, the error of the transfer operation is probed by charge counting. Error rates for extra (P+) or missing (P−) electrons of the electron shuttle are measured to P− = (6.92 ± 0.14) × 10 −5 and P+ = (2.13 ± 0.08) × 10 −5 with uncertainty due to correlated noise in the environment. Furthermore, precise control over the timing of the random walk allows to explore the role of memory as the clock frequency is increased.

show abstract

Robust formation of quantum dots in GaAs/AlGaAs heterostructures for single-electron metrology

Cited by 11 publications

References 25 publications

Thermoelectricity in Quantum Hall Corbino Structures

Thermoelectricity in Quantum Hall Corbino Structures

A random-walk benchmark for single-electron circuits

A random-walk benchmark for single-electron circuits

Contact Info

Product

Resources

About