scholarly journals From chemical soup to computing circuit: transforming a contiguous chemical medium into a logic gate network by modulating its external conditions

2019 ◽  
Vol 16 (158) ◽  
pp. 20190190
Author(s):  
Matthew Egbert ◽  
Jean-Sébastien Gagnon ◽  
Juan Pérez-Mercader
Keyword(s):  
Logic Gate ◽  
Reaction Diffusion ◽  
Logic Gates ◽  
Full Adder ◽  
Integrated Network ◽  
Lighting Conditions ◽  
Reaction Diffusion Model ◽  
Spatially Extended ◽  
External Conditions ◽  
Spatially Extended Systems

It has been shown that it is possible to transform a well-stirred chemical medium into a logic gate simply by varying the chemistry’s external conditions (feed rates, lighting conditions, etc.). We extend this work, showing that the same method can be generalized to spatially extended systems. We vary the external conditions of a well-known chemical medium (a cubic autocatalytic reaction–diffusion model), so that different regions of the simulated chemistry are operating under particular conditions at particular times. In so doing, we are able to transform the initially uniform chemistry, not just into a single logic gate, but into a functionally integrated network of diverse logic gates that operate as a basic computational circuit known as a full-adder.

Critical Slowing-Down of Spatially Nonhomogeneous Patterns in a Reaction–Diffusion Model

1997 ◽  
Vol 11 (14) ◽  
pp. 1717-1730 ◽  
Author(s):  
Fernando Castelpoggi ◽  
Horacio S. Wio ◽  
Damian H. Zanette
Keyword(s):  
Diffusion Model ◽  
Lyapunov Functional ◽  
Reaction Diffusion ◽  
Critical Slowing Down ◽  
Threshold Parameter ◽  
Extended System ◽  
Slowing Down ◽  
Reaction Diffusion Model ◽  
Spatially Extended ◽  
Nonequilibrium Potential

We exploit the concept of the nonequilibrium potential in order to analize the approach to stationary homogeneous and nonhomogeneous equilibrium states in a bounded bistable reaction-diffusion model. The analysis proceeds through the study of the Lyapunov functional, in terms of a control parameter -the threshold parameter ϕc-in the neighbourghood of a critical point (where a stable and an unstable pattern coalesce), that clearly shows the phenomenon of critical slowing-down in a spatially extended system.

scholarly journals Design of Gates for Quantum Computation: The NOT Gate

1997 ◽  
Vol 11 (18) ◽  
pp. 2207-2215
Author(s):  
Dima Mozyrsky ◽  
Vladimir Privman ◽  
Steven P. Hotaling
Keyword(s):  
Quantum Logic ◽  
Logic Gate ◽  
Logic Gates ◽  
Time Dependent ◽  
Practical Realization ◽  
Quantum Logic Gate ◽  
Quantum Logic Gates ◽  
Gate Circuit ◽  
Spatially Extended ◽  
Analog Approach

We offer an alternative to the conventional network formulation of quantum computing. We advance the analog approach to quantum logic gate/circuit construction. As an illustration, we consider the spatially extended NOT gate as the first step in the development of this approach. We derive an explicit form of the interaction Hamiltonian corresponding to this gate and analyze its properties. We also discuss general extensions to the case of certain time-dependent interactions which may be useful for practical realization of quantum logic gates.

A REACTION–DIFFUSION MODEL FOR THE CONTROL OF CHOLERA EPIDEMIC

2016 ◽  
Vol 24 (04) ◽  
pp. 431-456 ◽  
Author(s):  
A. K. MISRA ◽  
ALOK GUPTA
Keyword(s):  
Temporal Dynamics ◽  
Temporal Distribution ◽  
Reaction Diffusion ◽  
Effective Control ◽  
Lytic Bacteriophage ◽  
Cholera Epidemic ◽  
Reaction Diffusion Model ◽  
Spatially Extended ◽  
Control Procedures ◽  
Spatio Temporal

Understanding the spatio-temporal dynamics of cholera outbreaks may help in devising more effective control procedures. In this paper, we have considered a reaction–diffusion system for biological control of cholera epidemic. Firstly, we have focused on temporal evolution of cholera in a region and its control using lytic bacteriophage in the aquatic reservoirs. Then, we have explored the effect of spatial dispersion of populations on the disease dynamics. We have observed the onset of sustained oscillations via Hopf-bifurcation for the endemic state of temporal system. This onset of fluctuations in populations depends upon the phage adsorption rate. But in the spatially extended setting, all the populations stabilize i.e., the spatio-temporal distribution of all the populations becomes uniform. Some numerical computations have been done to verify analytical results.

scholarly journals Design and Implementation of New Coplanar FA Circuits without NOT Gate and Based on Quantum-Dot Cellular Automata Technology

2021 ◽  
Vol 11 (24) ◽  
pp. 12157
Author(s):  
Mohsen Vahabi ◽  
Pavel Lyakhov ◽  
Ali Newaz Bahar ◽  
Khan A. Wahid
Keyword(s):  
Cellular Automata ◽  
Quantum Dot ◽  
Logic Gate ◽  
Logic Gates ◽  
Full Adder ◽  
Cmos Technology ◽  
Ultra Low Power ◽  
Xor Gate ◽  
Design Complexity ◽  
Quantum Dot Cellular Automata

The miniaturization of electronic devices and the inefficiency of CMOS technology due to the development of integrated circuits and its lack of responsiveness at the nanoscale have led to the acquisition of nanoscale technologies. Among these technologies, quantum-dot cellular automata (QCA) is considered one of the possible replacements for CMOS technology because of its extraordinary advantages, such as higher speed, smaller area, and ultra-low power consumption. In arithmetic and comparative circuits, XOR logic is widely used. The construction of arithmetic logic circuits using AND, OR, and NOT logic gates has a higher design complexity. However, XOR gate design has a lower design complexity. Hence, the efficient and optimized XOR logic gate is very important. In this article, we proposed a new XOR gate based on cell-level methodology, with the expected output achieved by the influence of the cells on each other; this design method caused less delay. However, this design was implemented without the use of inverter gates and crossovers, as well as rotating cells. Using the proposed XOR gate, two new full adder (FA) circuits were designed. The simulation results indicate the advantage of the proposed designs compared with previous structures.

scholarly journals ORGANIC MEMRISTOR DEVICES FOR LOGIC ELEMENTS WITH MEMORY

2012 ◽  
Vol 22 (11) ◽  
pp. 1250283 ◽  
Author(s):  
VICTOR EROKHIN ◽  
GERARD DAVID HOWARD ◽  
ANDREW ADAMATZKY
Keyword(s):  
Low Power ◽  
Logic Gate ◽  
Logic Gates ◽  
Full Adder ◽  
Experimental Results ◽  
Boolean Logic ◽  
Next Generation ◽  
Nanoscale Fabrication ◽  
Thresholding Function ◽  
With Memory

Memristors are promising next-generation memory candidates that are nonvolatile, possess low power requirements and are capable of nanoscale fabrication. In this article, we physically realize and describe the use of organic memristors in designing stateful boolean logic gates for the AND OR and NOT operations. The output of these gates is analog and dependent on the length of time that suitable charge is applied to the inputs, displaying a learning property. Results may be also interpreted in a traditional binary manner through the use of a suitable thresholding function at the output. The memristive property of the gate allows for the production of analog outputs that vary based on the charge-dependent nonvolatile state of the memristor. We provide experimental results of physical fabrication of three types of logic gate. A simulation of a one-bit full adder comprised of memristive logic gates is also included, displaying varying response to two distinct input patterns.

scholarly journals Dynamic modulation of external conditions can transform chemistry into logic gates

2018 ◽  
Vol 15 (144) ◽  
pp. 20180169 ◽  
Author(s):  
Matthew Egbert ◽  
Jean-Sébastien Gagnon ◽  
Juan Pérez-Mercader
Keyword(s):  
Feed Rate ◽  
Logic Gates ◽  
Open Loop ◽  
Nand Gate ◽  
Dynamic Regulation ◽  
Logical Operators ◽  
Chemical Systems ◽  
Dynamic Modulation ◽  
Lighting Conditions ◽  
External Conditions

We introduce a new method for transforming chemical systems into desired logical operators (e.g. NAND gates) or similar signal-manipulation components. The method is based upon open-loop dynamic regulation, where external conditions such as feed-rate, lighting conditions, etc., are modulated according to a prescribed temporal sequence that is independent of the input to the network. The method is first introduced using a simple didactic model. We then show its application in transforming a well-stirred cubic autocatalytic reaction (often referred to as the Selkov–Gray–Scott model) into a logical NAND gate. We also comment on the applicability of the method to biological and other systems.

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