How fast can vanadium dioxide neuron-mimicking devices oscillate? Physical mechanisms limiting the frequency of vanadium dioxide oscillators - LIRMM - Laboratoire d’Informatique, de Robotique et de Microélectronique de Montpellier Access content directly
Journal Articles Neuromorphic Computing and Engineering Year : 2023

How fast can vanadium dioxide neuron-mimicking devices oscillate? Physical mechanisms limiting the frequency of vanadium dioxide oscillators

Andrew Plews
Ahmed Nejim
Siegfried Karg

Abstract

The frequency of vanadium dioxide (VO 2 ) oscillators is a fundamental figure of merit for the realization of neuromorphic circuits called oscillatory neural networks (ONNs) since the high frequency of oscillators ensures low-power consuming, real-time computing ONNs. In this study, we perform electrothermal 3D technology computer-aided design (TCAD) simulations of a VO 2 relaxation oscillator. We find that there exists an upper limit to its operating frequency, where such a limit is not predicted from a purely circuital model of the VO 2 oscillator. We investigate the intrinsic physical mechanisms that give rise to this upper limit. Our TCAD simulations show that it arises a dependence on the frequency of the points of the curve current versus voltage across the VO 2 device corresponding to the insulator-to-metal transition (IMT) and metal-to-insulator transition (MIT) during oscillation, below some threshold values of C e x t . This implies that the condition for the self-oscillatory regime may be satisfied by a given load-line in the low-frequency range but no longer at higher frequencies, with consequent suppression of oscillations. We note that this variation of the IMT/MIT points below some threshold values of C e x t is due to a combination of different factors: intermediate resistive states achievable by VO 2 channel and the interplay between frequency and heat transfer rate. Although the upper limit on the frequency that we extract is linked to the specific VO 2 device we simulate, our findings apply qualitatively to any VO 2 oscillator. Overall, our study elucidates the link between electrical and thermal behavior in VO 2 devices that sets a constraint on the upper values of the operating frequency of any VO 2 oscillator.
Fichier principal
Vignette du fichier
Carapezzi_2023_Neuromorph_Comput_Eng_3_034010.pdf (1.88 Mo) Télécharger le fichier

Dates and versions

lirmm-04230790 , version 1 (06-10-2023)

Licence

Identifiers

Cite

Stefania Carapezzi, Andrew Plews, Gabriele Boschetto, Ahmed Nejim, Siegfried Karg, et al.. How fast can vanadium dioxide neuron-mimicking devices oscillate? Physical mechanisms limiting the frequency of vanadium dioxide oscillators. Neuromorphic Computing and Engineering, 2023, 3 (3), pp.034010. ⟨10.1088/2634-4386/acf2bf⟩. ⟨lirmm-04230790⟩
32 View
31 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More