A single-electron stochastic associative processing circuit robust to random background-charge effects and its structure using nanocrystal floating-gate transistors

Abstract

A new single-electron circuit using the unique features of single-electron devices is proposed, based on a basic strategy and circuit architecture for achieving large-scale integration. A unit circuit consisting of a single-electron transistor and a capacitor operates as an exclusive-NOR gate by the Coulomb blockade effect, and its transient behaviour is stochastic due to electron-tunnelling events. Using this unit circuit, a stochastic associative processing circuit is proposed, based on a new information-processing principle where the association probability depends on the similarity between the input and reference data. This circuit can be constructed by using a silicon nanocrystal floating-gate structure in which dots are regularly arranged on a gate electrode of a MOSFET. The simulation results of a simple digit pattern association demonstrate the successful stochastic operation. The background-charge effects on the proposed circuit are analysed and simulated, and it is shown that the circuit is much more robust to such effects than the conventional single-electron logic circuits.

Associative Memory Based on Double-Gating of Molecularly Linked Nanosystem Arrays: A Theoretical Scheme

“…The capacitor that reaches this prescribed potential at a shorter time corresponds to the pattern i most similar to the input pattern (the number 5 in Figures 6 and 7). 2 As expected, the maximum potentials of Figure 6 decrease with increasing the Hamming distance for the patterns of Figure 2. Note that disordered patterns similar but not exactly equal to any of the stored patterns may also be used as input patterns by introducing the appropriate values of HD i in eqs 4 and 7 for each pair of input and stored patterns.…”

“…We start here from the single-electron, stochastic, associative processing circuit by Yamanaka et al 2 and propose an associative memory based on the ideal conductive properties of a molecularly linked nanosystem array. Two schemes are studied.…”

“…2 The Monte Carlo simulation and master equation methods for circuit analysis may be employed, but they are time-consuming, 1,4,5,28 especially for nanoscaled circuits with many basic units. 2,3 Moreover, established theoretical approaches for electronic tunneling through junctions of ideal SETs cannot be directly applied to disordered arrays, and corrections are usually needed in networks of nanoscale metallic islands separated by insulating ligands.…”

Synchronization of coupled single-electron circuits based on nanoparticles and tunneling junctions

“…However, it is also necessary to design general schemes that could perform information storage and processing tasks using well-defined nanostructures at the ideal circuit level. 7,8,[10][11][12] We have recently proposed a device that uses nanoscale switches to implement a signal processing scheme and a frequency-dependent associative memory. 13 In this article, we explore theoretically the synchronization of coupled single-electron circuits whose building blocks are nanoparticles interconnected with tunneling junctions.…”

“…10,14,15 Elementary nanoscillators can be achieved by a singleelectron tunneling cell where the relaxation oscillation is induced by the tunneling. [14][15][16][17] The tunnel junction acts as a leaky capacitor that can be controlled by the voltage across the junction and, because of the scale at which transport occurs, the transference of a few electrons may suffice to implement a variety of electronic functions.…”