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Decision trees within a molecular memristor.

Authors :
Goswami, Sreetosh
Pramanick, Rajib
Patra, Abhijeet
Rath, Santi Prasad
Foltin, Martin
Ariando, A.
Thompson, Damien
Venkatesan, T.
Goswami, Sreebrata
Williams, R. Stanley
Source :
Nature; 9/2/2021, Vol. 597 Issue 7874, p51-56, 6p
Publication Year :
2021

Abstract

Profuse dendritic-synaptic interconnections among neurons in the neocortex embed intricate logic structures enabling sophisticated decision-making that vastly outperforms any artificial electronic analogues1–3. The physical complexity is far beyond existing circuit fabrication technologies: moreover, the network in a brain is dynamically reconfigurable, which provides flexibility and adaptability to changing environments4–6. In contrast, state-of-the-art semiconductor logic circuits are based on threshold switches that are hard-wired to perform predefined logic functions. To advance the performance of logic circuits, we are re-imagining fundamental electronic circuit elements by expressing complex logic in nanometre-scale material properties. Here we use voltage-driven conditional logic interconnectivity among five distinct molecular redox states of a metal–organic complex to embed a ‘thicket’ of decision trees (composed of multiple if-then-else conditional statements) having 71 nodes within a single memristor. The resultant current–voltage characteristic of this molecular memristor (a 'memory resistor', a globally passive resistive-switch circuit element that axiomatically complements the set of capacitor, inductor and resistor) exhibits eight recurrent and history-dependent non-volatile switching transitions between two conductance levels in a single sweep cycle. The identity of each molecular redox state was determined with in situ Raman spectroscopy and confirmed by quantum chemical calculations, revealing the electron transport mechanism. Using simple circuits of only these elements, we experimentally demonstrate dynamically reconfigurable, commutative and non-commutative stateful logic in multivariable decision trees that execute in a single time step and can, for example, be applied as local intelligence in edge computing7–9.Multiple redox transitions in a molecular memristor can be harnessed as ‘decision trees’ to undertake complex and reconfigurable logic operations in a single time step. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00280836
Volume :
597
Issue :
7874
Database :
Complementary Index
Journal :
Nature
Publication Type :
Academic Journal
Accession number :
152218725
Full Text :
https://doi.org/10.1038/s41586-021-03748-0