Long-Term Charge Offset Noise in Coulomb-Blockade Devices

Published

January 9, 2001

Author(s)

William Huber, S Martin, Neil M. Zimmerman

Abstract

While Coulomb-Blockade devices have shown promise as qubit systems or qubit state detectors, large scale parallelization of these devices is severely hampered due to the low-frequency charge offset (Q₀) drift in time. We note that an extrapolation of the 1/f noise to lower frequencies cannot account for the large (δQ₀ 1 e) changes. We have investigated possible approaches towards reducing the Q0 noise in Al/Al₂O_3-x/Al based Coulomb-Blockade (CB) devices. In Al/Al₂O_3-x/Al-based CB devices, the maximum stability was typically 1 day to 3 days, nearly independent of processing techniques or annealing treatments. In our best result, δQ₀ < 0.1 e (except for a single excursion) for 12 days. Encasing devices in a continuous metal vault (a nano-Faraday cage) did not, however, improve the Q₀ noise. We also discuss one specific, identified cause of the low frequency (< 10³ Hz) Q₀ noise. By extending conventional, two-level system theory (previously used to explain the behavior of macroscopic disordered materials), the noise is shown to be caused by atomic structural relaxations of nearby insulating regions.

Proceedings Title

Proc., International Conference on the Experimental Implementation of Quantum Computing

Conference Dates

January 9-20, 2001

Conference Location

Sydney, 1, AS

Conference Title

International Conference on the Experimental Implementation of Quantum Computing

Pub Type

Conferences

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Keywords

charge offset, Faraday screening, low temperature glass dynamics, single-electron tunneling

Citation

Huber, W. , Martin, S. and Zimmerman, N. (2001), Long-Term Charge Offset Noise in Coulomb-Blockade Devices, Proc., International Conference on the Experimental Implementation of Quantum Computing, Sydney, 1, AS, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=30222 (Accessed April 26, 2024)