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arXiv · 1306.4229

Cryogenic on-chip multiplexer for the study of quantum transport in 256 split-gate devices

H. Al-Taie·L. W. Smith·B. Xu·P. See·J. P. Griffiths·H. E. Beere·G. A. C. Jones·D. A. Ritchie·M. J. Kelly·C. G. Smith
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Abstract

We present a multiplexing scheme for the measurement of large numbers of mesoscopic devices in cryogenic systems. The multiplexer is used to contact an array of 256 split gates on a GaAs/AlGaAs heterostructure, in which each split gate can be measured individually. The low-temperature conductance of split-gate devices is governed by quantum mechanics, leading to the appearance of conductance plateaux at intervals of 2e^2/h. A fabrication-limited yield of 94% is achieved for the array, and a "quantum yield" is also defined, to account for disorder affecting the quantum behaviour of the devices. The quantum yield rose from 55% to 86% after illuminating the sample, explained by the corresponding increase in carrier density and mobility of the two-dimensional electron gas. The multiplexer is a scalable architecture, and can be extended to other forms of mesoscopic devices. It overcomes previous limits on the number of devices that can be fabricated on a single chip due to the number of electrical contacts available, without the need to alter existing experimental set ups.

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H. Al-Taie, L. W. Smith, B. Xu, P. See, J. P. Griffiths, H. E. Beere, G. A. C. Jones, D. A. Ritchie, M. J. Kelly, C. G. Smith. 2013-06-18. Cryogenic on-chip multiplexer for the study of quantum transport in 256 split-gate devices. https://doi.org/10.1063/1.4811376

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