N-state random switching based on quantum tunnelling

Bernardo Gavito, Ramon and J. Urbanos, F. and Roberts, Jonny and Sexton, J. and Astbury, Benjamin and Shokeir, Hamzah and Mcgrath, Thomas and Noori, Yasir and Woodhead, Christopher Stephen and Missous, Mohammed and Roedig, Utz and Young, Robert James (2017) N-state random switching based on quantum tunnelling. Proceedings of SPIE, 10354. 103541T. ISSN 0277-786X

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In this work, we show how the hysteretic behaviour of resonant tunnelling diodes (RTDs) can be exploited for new functionalities. In particular, the RTDs exhibit a stochastic 2-state switching mechanism that could be useful for random number generation and cryptographic applications. This behaviour can be scaled to N-bit switching, by connecting various RTDs in series. The InGaAs/AlAs RTDs used in our experiments display very sharp negative differential resistance (NDR) peaks at room temperature which show hysteresis cycles that, rather than having a fixed switching threshold, show a probability distribution about a central value. We propose to use this intrinsic uncertainty emerging from the quantum nature of the RTDs as a source of randomness. We show that a combination of two RTDs in series results in devices with three-state outputs and discuss the possibility of scaling to N-state devices by subsequent series connections of RTDs, which we demonstrate for the up to the 4-state case. In this work, we suggest using that the intrinsic uncertainty in the conduction paths of resonant tunnelling diodes can behave as a source of randomness that can be integrated into current electronics to produce on-chip true random number generators. The N-shaped I-V characteristic of RTDs results in a two-level random voltage output when driven with current pulse trains. Electrical characterisation and randomness testing of the devices was conducted in order to determine the validity of the true randomness assumption. Based on the results obtained for the single RTD case, we suggest the possibility of using multi-well devices to generate N-state random switching devices for their use in random number generation or multi-valued logic devices.

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Journal Article
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Proceedings of SPIE
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Ramón Bernardo Gavito, Fernando Jiménez Urbanos, Jonathan Roberts, James Sexton, Benjamin Astbury, Hamzah Shokeir, Thomas McGrath, Yasir J. Noori, Christopher S. Woodhead, Mohamed Missous, Utz Roedig, Robert J. Young, "N-state random switching based on quantum tunnelling", Proc. SPIE 10354, Nanoengineering: Fabrication, Properties, Optics, and Devices XIV, 103541T (31 August 2017); doi: 10.1117/12.2273298; http://dx.doi.org/10.1117/12.2273298 Copyright 2017 Society of Photo Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, or modification of the contents of the publication are prohibited.
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08 Nov 2017 09:34
Last Modified:
05 Jun 2024 00:30