Controlling Losses With Gates and Shields to Perfect a Quantum Hall Impedance Standard

Schurr, J.; Kibble, B P; Hein, G.; Pierz, K.

doi:10.1109/tim.2008.2006961

Cited by 18 publications

(37 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…were published recently [14,15]. In these papers the present model of the frequency and cur-rent dependences of the quantum Hall effect was addressed and confirmed, and three different loss mechanisms in ac-QHR measurements were identified.…”

Section: Summary Of the Modelsmentioning

confidence: 82%

“…In these papers the present model of the frequency and cur-rent dependences of the quantum Hall effect was addressed and confirmed, and three different loss mechanisms in ac-QHR measurements were identified. A special double-shielded configuration proposed in [14,15] allowed to eliminate the effect of all three loss mechanisms so that the ac QHR became independent of frequency and current, and an excellent relative uncertainty below 1 × 10 -8 could be achieved which is a significant improvement in the setup for using the ac QHR as a precise quantum standard of impedance. When the new findings from [14,15] will have been confirmed by other NMIs, a future version of this compendium will advise in detail how to achieve the uncertainty of 1 part in 10 8 or lower for the ac QHR.…”

Section: Summary Of the Modelsmentioning

confidence: 99%

“…After the first precision ac measurement of the QHR had demonstrated an accuracy of a few parts in 10 6 [4], considerable progress has been made on the subject of accurate ac QHR measurements [5][6][7][8][9][10][11][12][13][14][15]. Today, measurements with carefully set up ac bridges achieve an uncertainty of a few parts in 10 8 , and agreement at this level has been achieved between different NMIs.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Compendium for precise ac measurements of the quantum Hall resistance

et al. 2009

View full text Add to dashboard Cite

Abstract. In view of the progress achieved in the field of the ac quantum Hall effect, the Working Group of the Comité Consultatif d'Électricité et Magnétisme (CCEM) on the AC Quantum Hall Effect asked the authors of this paper to write a compendium which integrates their experiences with ac measurements of the quantum Hall resistance. In addition to the important early work performed at the Bureau International des Poids et Mesures and the National Physical Laboratory, UK, further experience has been gained during a collaboration of the authors' institutes NRC, METAS, and PTB, and excellent agreement between the results of different national metrology institutes has been achieved. This compendium summarizes the present state of the authors' knowledge and reviews the experiences, tests and precautions that the authors have employed to achieve accurate measurements of the ac quantum Hall effect. This work shows how the ac quantum Hall effect can be reliably used as a quantum standard of ac resistance having a relative uncertainty of a few parts in 10 8 .

show abstract

Section: Summary Of the Modelsmentioning

confidence: 82%

Section: Summary Of the Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Compendium for precise ac measurements of the quantum Hall resistance

et al. 2009

View full text Add to dashboard Cite

show abstract

“…If no precautions are taken, the ac quantum Hall resistance (QHR) exhibits an unwanted frequency-and current-dependence which is attributed to ac losses of internal and external capacitances of the QHR device [1]. In the past, this limited the application as a quantum impedance standard.…”

Section: Introductionmentioning

confidence: 99%

“…Two different loss mechanisms have to be distinguished. The dominating loss factor is related to electric ac fields which have a component in the plane of the 2DEG, and it exhibits a characteristic proportionality to the current [1]. Examples are the internal capacitances in the 2DEG and the cross capacitances between the edges of the 2DEG and the double-shield.…”

Section: Introductionmentioning

confidence: 99%

A quantum impedance standard having an insignificant, experimentally verified frequency dependence

et al. 2010

Self Cite

View full text Add to dashboard Cite

Recently we have published a novel double-shield configuration of quantum Hall devices to eliminate the effect of all presently known ac losses within 3×10 −9 kHz −1 . Now we have further verified the double-shielding technique by supporting the experimental findings with a model. This model indicates that it should be possible to reduce the frequency dependence to less than 1×10 −9 kHz −1 , which would be better than our ultimate measuring limit and much better than our calculable impedance artefacts. Thereby, the ac quantum Hall impedance closely approaches a perfect quantum standard.

show abstract