Single Logic Gate Research Articles

Long distance all-optical logic operations through a single multimode fiber empowered by wavefront shaping

Multimode fibers (MMFs) are a promising solution for high-throughput signal transmission in the time domain. However, crosstalk among different optical modes within the MMF scrambles input information and creates seemingly random speckle patterns at the output. To characterize this process, a transmission matrix (TM) can be used to relate input and output fields. Recent innovations use TMs to manipulate the output field by shaping the input wavefront for exciting advances in deep-brain imaging, neuron stimulation, quantum networks, and analog operators. However, these approaches consider input/output segments as independent, limiting their use for separate signal processing, such as logic operations. Our proposed method, which makes input/output segments as interdependent, adjusts the phase of corresponding output fields using phase bias maps superimposed on input segments. Coherent superposition enables signal logic operations through a 15-m-long MMF. In experiments, a single optical logic gate containing three basic logic functions and cascading multiple logic gates to handle binary operands is demonstrated. Bitwise operations are performed for multi-bit logic operations, and multiple optical logic gates are reconstructed simultaneously in a single logic gate with polarization multiplexing. The proposed method may open new avenues for long-range logic signal processing and transmission via MMFs.

A Chromo-fluorogenic Probe for Selective Detection of Picric Acid Alongside Its Recovery by Aliphatic Amines and Construction of Molecular Logic Gates.

Nitroaromatic compounds are illicit explosive chemicals. For environmental security and homeland safety, selective and sensitive identification of these secondary-class explosives has been a reason for the exhaustive research arena of chemists for about a decade. We introduced a sensitive optical sensor with desalted neutral red (NR) dye. After ingressing picric acid (PA) in acetonitrile, the probe becomes non-fluorescent, displaying a colorimetric changefrom yellow to pink. The quenched phenomena and the changed color were re-established with aliphatic amine, trimethylamine (TEA). The reversibility is produced cyclically, both in fluorimetrically and spectrophotometrically. The detection limit for PA with our probe comes out as 0.639µM; this value is significantly lower than many chemosensors available in the literature. Also, NR-stained filter paper strips-based test kit analysis has been deployed as a displayable photonic device for in-situ detection of PA. Furthermore, the whole system was conceptualized to produce single input, single output, and double input single output logic gates, which can be applied to digital devices. The chronological input manner as NTP (NR- TEA-PA) pushed us to configure a molecular keypad lock system, the basis of digital locking devices. The repeatable & reversible detection system exhibits "Write read- Erase-read Write-read' type memory devices.

Splitter trees of superconducting nanowire cryotrons for large fan-out

A fan-out circuit is a basic block for scaling up digital circuits for overcoming the limited driving capability of a single logic gate. It is particularly important for superconducting digital circuits as the driving power is typically weak for having high energy efficiency. Here, we design and fabricate a fan-out circuit for a superconducting nanowire cryotron (nTron) digital circuit. A classic splitter tree architecture is adopted. To transmit switching signal and avoid crosstalk among nTrons, we introduced an “R–L–R” interface circuit. Experimentally, a two-stage splitter tree of a fan-out number of four was demonstrated. Correct operation was observed with a minimum bit error rate (BER) of 10−6. The bias margin was 10% at BER of 10−4. The average time jitter was 82 ps. Moreover, crosstalk was not observed. Based on these results, we envision that the fan-out circuit can be used in future development of superconducting-nanowire-based circuits.

Research progress of quantum coherence performance and applications of micro/nano scale rare-earth doped crystals

Rare-earth ion doped crystals possess stable solid state physicochemical properties and long optical coherence time and spin coherence time, thus showing important development prospect in quantum information science and technology area. Investigations on macroscopic bulk rare-earth single crystals have obtained many promising results, especially in the field of optical quantum memory. With the rapid development of quantum information science, a variety of new functions or multifunctional integrations are found in rare earth crystal systems, such as on chip quantum storage, microwave to optical frequency conversion, scalable quantum single photon sources, and quantum logic gates. As a result, beyond the macroscopic bulk rare-earth single crystals, micro/nano-scale rare-earth crystals have received much attention in recent years and they are regarded as promising candidates in highly integrated hybrid quantum systems and miniaturized quantum devices. Moreover, wet chemical method synthesized micro/nano-scale rare-earth crystals have lower growth difficulty and more flexible manipulation in volume, shape and composition. Therefore, exploring high-performance micro/nano-scale rare-earth crystals and precisely manipulating their quantum states have become one of the important directions in today’s quantum information science and technology research. In this review, we first briefly introduce the basic concepts and high resolution spectroscopic techniques that are commonly used in rare earth ion doped crystals for quantum information science and technologies, such as hole burning technique and photon echo technique. Then we summarize comprehensively recent research status and development trends of rare earth ion doped polycrystalline nanoparticles, thin films, single crystal based micro systems, and some other micro/nano-scale rare earth platforms in terms of material fabrication, quantum coherence property, dephasing mechanisms, and also quantum device explorations. The latest research advances in quantum information applications such as quantum storage, quantum frequency conversion, quantum single photon sources and quantum logic gates are given. Finally, we discuss the possible optimization directions and strategies to improve the component design, material synthesis and quantum performance of micro/nano-scale rare earth crystals and their related quantum devices. This review highlights that the micro/nano-scale rare earth crystals may offer many new possibilities for designing quantum light-matter interfaces, thus are promising quantum systems to develop scalable and integrated quantum devices in the future.

CNTFET-based design of ternary logic gates with interchangeable standard positive and negative ternary output

This paper presents a novel CNTFET based design of ternary logics gates where all three ternary logics including standard, positive and negative ternary logic (ST, PT and NT) outputs for each gate are obtained from one structure and are interchangeable through some control inputs. Ternary logic overpowers the conventional binary logic in simplicity and energy efficiency as it reduces number of interconnects and chip area. In this paper design of ternary inverter, buffer, NAND, AND, NOR, OR, XOR and XNOR gates are presented where a unique feature of conversion between ST, PT, NT logic through a single output is being introduced. Besides a single logic gate is designed for a particular logic function and its complement combining both ternary and binary logic gate design technique. The proposed designs utilize the unique property of CNTFET, such as assigning the required threshold voltage value of the FET by changing the diameter of the carbon nanotube (CNT) through its chiral vector values which is very useful in designing multiple- valued logic (here ternary logic). The proposed circuits are simulated using Synopsys HSPICE with 32 nm CNTFET model provided by Stanford University and in each case average power values and propagation delays are duly noted. The effects of variation in some process parameters like channel length, dielectric oxide thickness and number of carbon nanotubes also have been discussed.

Frequency Doubler and Universal Logic Gate Based on Two-Dimensional Transition Metal Dichalcogenide Transistors with Low Power Consumption.

Two-dimensional transition metal dichalcogenide semiconductors are very promising candidates for future electronic applications with low power consumption due to a low leakage current and high on-off current ratio. In this study, we suggest a complementary circuit consisting of ambipolar WSe2 and n-MoS2 field-effect transistors (FETs), which demonstrate dual functions of a frequency doubler and single inversion AND (SAND) logic gate. In order to reduce the power consumption, a high-quality thin h-BN single crystal is used as a gate dielectric that leads to a low operating voltage of less than 5 V. By combining the low operating voltage with a low operating current in the complementary circuit, a low power consumption of 300 nW (a minimum of 10 pW) has been achieved, which is a significant improvement compared to the tens of μW consumed by a graphene channel. The complementary circuit shows the effective frequency doubling of the input with a dynamic range from 20 to 100 Hz. Furthermore, this circuit satisfies all the truth tables of a SAND logic gate that can be used as a universal logic gate like NAND. Considering that the NAND logic gate generally consists of four transistors, it is significantly advantageous to implement the equivalent circuit SAND logic gate with only two FETs. Our results open up possibilities for analog- and logic-circuit applications based on low-dimensional semiconductors.

On-the-analysis and reduction of common-mode voltage of a single-stage inverter through control of a four-leg-based topology

This paper presents a three-phase four-leg-based split-source inverter (SSI) topology to reduce its instantaneous common-mode (CM) voltage. The proposed topology utilizes a simple discontinuous pulse width modulation (DPWM) strategy based on imaginary switching times (ISTs) with a single Boolean logic gate to drive the fourth leg. The paper first presents a brief analysis of the CM voltage issue in the available SSI equipped with different control techniques. Then, the principle of operation and the analysis of the proposed four-leg-based SSI topology along with the proposed modulation technique are introduced. Moreover, the output filter inductance’s effect on the CM voltage levels is examined and the results are provided. To verify the effectiveness and demonstrate the performance of the proposed inverter topology with the associated modulation strategy, a Simulink model has been designed, evaluated and then verified with experiments with different case studies and modulation strategies. The obtained results show that the proposed four-leg-based SSI with the proposed modulation strategy not only restrains the instantaneous peak-to-peak CM voltage but also reduces the number of switching transitions in the resultant CM voltage.

Stochastic computing in convolutional neural network implementation: a review

Stochastic computing (SC) is an alternative computing domain for ubiquitous deterministic computing whereby a single logic gate can perform the arithmetic operation by exploiting the nature of probability math. SC was proposed in the 1960s when binary computing was expensive. However, presently, SC started to regain interest after the widespread of deep learning application, specifically the convolutional neural network (CNN) algorithm due to its practicality in hardware implementation. Although not all computing functions can translate to the SC domain, several useful function blocks related to the CNN algorithm had been proposed and tested by researchers. An evolution of CNN, namely, binarised neural network, had also gained attention in the edge computing due to its compactness and computing efficiency. This study reviews various SC CNN hardware implementation methodologies. Firstly, we review the fundamental concepts of SC and the circuit structure and then compare the advantages and disadvantages amongst different SC methods. Finally, we conclude the overview of SC in CNN and make suggestions for widespread implementation.

Reliability-Aware Design Strategies for Stateful Logic-in-Memory Architectures

The in-memory computation of logic operations is a promising paradigm that could enable the development of highly efficient computing architectures, ideal for battery-powered devices. Indeed, Resistive Random Access Memory (RRAM) devices and the material implication logic (IMPLY) have been experimentally demonstrated to enable low-power logic-in-memory (LIM) circuits. Still, device and circuit non-idealities (e.g., the strong sensitivity to driving voltage variations) introduce several reliability challenges that must be addressed with appropriate device models. Often, general-purpose or simplified models are used in the analysis, thus resulting in questionable estimations and designs. In this work, we use a physics-based RRAM compact model, comprehensive of device non-idealities, to study the reliability of IMPLY-based LIM circuits. The analysis is first performed on the single IMPLY logic gate and then extended to an array implementation encompassing the effect of line parasitic resistances and node capacitances. We determine and quantitatively evaluate important metrics such as energy consumption and maximum array size, and derive appropriate design strategies aimed at improving the reliability of such circuits.

Implementation of Quantum Gates using MATLAB

Now days we require low cost and high performance computational based applications. Quantum inspired computational device or circuit performs effective result compare to classical based devices. In the development of quantum-based devices and network needs number of quantum logic gates. Here we studied mathematical description of different types of single and multiple qubits-based quantum logic gates, the reversibility property of quantum gates also proved mathematically. We analyze the cost and effectiveness of each quantum gates has been implemented using neural network with the help of MATLAB. The cost and effectiveness of quantum gates has been analyzed with the comparison of different types of activation function.

Dual macro-cyclic component based logic diversity

In continuation of our recent studies on the photophysics of a photodynamic therapeutic agent, harmine (HM) in model membrane, the present contribution highlights a new model to design multiple logic circuits, a memory device and a molecular lock regulated by dual macrocyclic components as chemical inputs. The unique reversible photoswitching regulated by macrocyclic components plays decisive role in the manifestation of the final outputs for the logic functions. Inspired by this phenomenon, herein, we are reporting the use of a photosensitizer molecule for designing of various logic circuits at molecular level with the intention to escalate the next generation molecular logic arena. For these desired outsets, fluorescence spectroscopic changes of HM upon addition of macrocyclic components (CTAB and β-CD) were utilised. Beyond the simple single input single output logic gates (NOT, YES, PASS 0 and PASS 1), we were also able to design IMPLICATION and INHIBIT gates. In addition to different logic functions, the modulations of the optical responses of HM driven by the macrocyclic components were employed to design “Erase-Read-Write-Read” and “Write-Read-Erase-Read” type memory units. Moreover, considering the optical responses of HM we proposed a supramolecular keypad lock operated through unique sequential entry of opto-chemical passwords.

Construction of Two-Input Logic Gates Using Transcriptional Interference.

Transcriptional interference (TI) has been shown to regulate gene expression at the DNA level via different molecular mechanisms. The obstacles present on the DNA that a transcribing RNA polymerase might encounter, for example, a DNA-bound protein or another RNA polymerase, can result in TI causing termination of transcription, thus reducing gene expression. However, the potential of TI as a new strategy to engineer complex gene expression modules has not been fully explored yet. Here we created a series of two-input genetic devices that use the presence of a roadblocking protein to control gene expression and analyzed their behaviors using both experimental and mathematical modeling approaches. We explored how multiple characteristics affect the response of genetic devices engineered to act like either AND, OR, or single input logic gates. We show that the dissociation constant of the roadblocking protein, inducer activation of promoter and operator sites, and distance between tandem promoters tune gate behavior. This work highlights the potential of rationally creating different types of genetic responses using the same transcription factors in subtly different genetic architectures.

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

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.

Bioinspired Nanozymes with pH‐Independent and Metal Ions‐Controllable Activity: Field‐Programmable Logic Conversion of Sole Logic Gate System

AbstractIn nature, different environmental factors make organisms to be programmed into different forms. However, it is difficult and significant to realize the field‐programmable logic conversion of sole logic system for molecular logic gates. Here, the concept of pH‐programmable “logic conversion” on the single logic gate based on the peculiar enzyme‐mimicking activity is presented. Inspired by natural enzymes with high pH‐stability and metal ions‐stimulated activity, pH‐independent and metal ions‐controllable catalase mimics (Co3O4 nanozymes) are designed by protein‐directed method. Although pH cannot directly change the activity of nanozymes, pH can change the existence state of metal ions and then the electron transfer rate on nanozymes. So, versatile roles of metal ions for catalase‐like and electrocatalytic activities are discovered on the premise of pH‐independency. For the proof‐of‐concept, OR/INHIBIT‐ and INHIBIT/AND‐switchable logic gates are facilely constructed using pH as the environmental stimulus and metal ions as inputs. Hence, the transformation of logic gate functions is realized without the change of logic gate elements and input molecules. This contribution may not only broaden the species and application area of nanozymes, but also open novel avenues for the molecular logic conversion and the metal ions sensor.

A single nano cantilever as a reprogrammable universal logic gate

The current transistor-based computing circuits use multiple interconnected transistors to realize a single Boolean logic gate. This leads to higher power requirements and delayed computing. Transistors are not suitable for applications in harsh environments and require complicated thermal management systems due to excessive heat dissipation. Also, transistor circuits lack the ability to dynamically reconfigure their functionality in real time, which is desirable for enhanced computing capability. Further, the miniaturization of transistors to improve computational power is reaching its ultimate physical limits. As a step towards overcoming the limitations of transistor-based computing, here we demonstrate a reprogrammable universal Boolean logic gate based on a nanoelectromechanical cantilever (NC) oscillator. The fundamental XOR, AND, NOR, OR and NOT logic gates are condensed in a single NC, thereby reducing electrical interconnects between devices. The device is dynamically switchable between any logic gates at the same drive frequency without the need for any change in the circuit. It is demonstrated to operate at elevated temperatures minimizing the need for thermal management systems. It has a tunable bandwidth of 5 MHz enabling parallel and dynamically reconfigurable logic device for enhanced computing.

Gated single molecular device and logic gate design

The electron transport properties of an electrostatic gated single molecular transistor are investigated by using self-consistent semi-empirical method. The charge transport characteristics of the molecular device are analysed through the current-voltage I SD−V SD characteristics transmission characteristics T (E), and molecular projected self-consistent Hamiltonian states analysis. It is revealed that the gate bias V G can effectively tune the transport properties to greater extent. The mechanisms governing the gate bias tuned transport properties in this device were discussed. The proposed device also exhibits gate modulated negative differential resistance feature, which is exploited in realising basic logic gates. Thus, by using source-drain resistance R as a function of V G, the application of using gated thiophene based molecular device to realise a set of five basic logic gates at particular V SD is shown. The significant feature of the proposed device is the possibility of realising different logic gates with just one molecular transistor using computationally inexpensive semi-empirical method.

Control of electrochemical signals from quantum dots conjugated to organic materials by using DNA structure in an analog logic gate

Various bio-logic gates have been studied intensively to overcome the rigidity of single-function silicon-based logic devices arising from combinations of various gates. Here, a simple control tool using electrochemical signals from quantum dots (QDs) was constructed using DNA and organic materials for multiple logic functions. The electrochemical redox current generated from QDs was controlled by the DNA structure. DNA structure, in turn, was dependent on the components (organic materials) and the input signal (pH). Independent electrochemical signals from two different logic units containing QDs were merged into a single analog-type logic gate, which was controlled by two inputs. We applied this electrochemical biodevice to a simple logic system and achieved various logic functions from the controlled pH input sets. This could be further improved by choosing QDs, ionic conditions, or DNA sequences. This research provides a feasible method for fabricating an artificial intelligence system.

Intelligent Nucleic Acid Functionalized Dual‐Responsive Gold Nanoflare: Logic‐Gate Nanodevice Visualized by Single‐Nanoparticle Imaging

AbstractAn intelligent nucleic acid functionalized dual‐responsive gold nanoflare was developed, and its exclusive‐OR (XOR) logic response was demonstrated by single‐nanoparticle imaging technology. Cy5 labelled adenosine aptamer and DNA molecule beacon were modified on the surface of gold nanoflares and consequence XOR logic‐gate operation was successfully achieved based on adenosine aptamer binding induced fluorescence quenching and cDNA bind triggered fluorescence recovery. Their photophysical properties, concentration‐dependent fluorescence variation and logic‐gate response were systematically studied at the single‐nanoparticle level. Single logic gate imaging demonstrated that a larger input was required to produce a change sufficient for single‐nanoparticle analysis, and the logic gate can be well used for a stimulated biologic process. This work will be significant in the future fabrication of nanodevices and DNA computer at single‐particle level.

A Hardware-Based Countermeasure to Reduce Side-Channel Leakage: Design, Implementation, and Evaluation

Side-channel attacks are one of the major concerns for security-enabled applications as they make use of information leaked by the physical implementation of the underlying cryptographic algorithm. Hence, reducing the side-channel leakage of the circuits realizing the cryptographic primitives is amongst the main goals of circuit designers. In this paper, we present a novel circuit concept, which decouples the main power supply from an internal power supply that is used to drive a single logic gate. The decoupling is done with the help of buffering capacitances integrated into semiconductor. We also introduce-compared to the previously known schemes-an improved decoupling circuit which reduces the crosstalk from the internal to the external power supply. The result of practical side-channel evaluation on a prototype chip fabricated in a 150nm CMOS technology shows a high potential of our proposed technique to reduce the side-channel leakages.

Lyapunov control on quantum systems

We review the scheme of quantum Lyapunov control and its applications into quantum systems. After a brief review on the general method of quantum Lyapunov control in closed and open quantum systems, we apply it into controlling quantum states and quantum operations. The control of a spin-1/2 quantum system, driving an open quantum system into its decoherence free subspace (DFS), constructing single qubit and two-qubit logic gates are taken to illustrate the scheme. The optimalization of the Lyapunov control is also reviewed in this article.