Mach-Zehnder interferometer-based all-optical reversible logic gate

In recent years, reversible logic has emerged as a promising computing paradigm having application in low-power CMOS, quantum computing, nanotechnology and optical computing. Optical logic gates have the potential to work at macroscopic (light pulses carry information), or quantum (single photons carry information) levels with great efficiency. However, relatively little has been published on designing reversible logic circuits in all-optical domain. In this paper, we propose and design a novel scheme of Toffoli and Feynman gates in all-optical domain. We have described their principle of operations and used a theoretical model to assist this task, finally confirming through numerical simulations. Semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (MZI) can play a significant role in this field of ultra-fast all-optical signal processing. The all-optical reversible circuits presented in this paper will be useful to perform different arithmetic (full adder, BCD adder) and logical (realization of Boolean function) operations in the domain of reversible logic-based information processing.     

飞秒激光直写光量子逻辑门

量子比特在同一时刻可处于所有可能状态上的叠加特性使得量子计算机具有天然的并行计算能力,在处理某些特定问题时具有超越经典计算机的明显优势.飞秒激光直写技术因其具有单步骤高效加工真三维光波导回路的能力,在制备通用型集成光量子计算机的基本单元—量子逻辑门中发挥着越来越重要的作用.本文综述了飞秒激光直写由定向耦合器构成的光量子比特逻辑门的进展.主要包括定向耦合器的功能、构成、直写和性能表征,集成波片、哈达玛门和泡利交换门等单量子比特逻辑门、受控非门和受控相位门等两量子比特逻辑门的直写加工,并对飞秒激光加工三量子比特逻辑门进行了展望.     

Realization of XNOR logic function with all-optical high contrast XOR and NOT gates

In this article, we propose the realization of XNOR logic function by using all-optical XOR and NOT logic gates. Initially, both XOR and NOT gates are designed, simulated and optimized for high contrast outputs. T-shaped waveguides are created on the photonic crystal platform to realize these logic gates. An extra input is used to perform the inversion operation in the NOT gate. Inputs in both the gates are applied with out of phase so as to have a destructive interference between them and produce negligible intensity for logic ‘0'. The XOR and NOT gates are simulated using Finite Difference Time Domain method which results with a high contrast ratio of 55.23?dB and 54.83?dB, respectively at a response time of 0.136?ps and 0.1256?ps. Later, both the gates are cascaded by superimposing the output branch of the waveguide of XOR gate with the input branch of the waveguide of NOT gate so that it can be resulted with compact size for XNOR logic function. The resultant structure of XNOR logic came out with the contrast ratio of 12.27?dB at a response time of 0.1588?ps. Finally, it can be concluded that the proposed structures with fair output performance can suitably be applied in the design of photonic integrated circuits for high speed computing and telecommunication systems.     

Entanglement as a Semantic Resource

The characteristic holistic features of the quantum theoretic formalism and the intriguing notion of entanglement can be applied to a field that is far from microphysics: logical semantics. Quantum computational logics are new forms of quantum logic that have been suggested by the theory of quantum logical gates in quantum computation. In the standard semantics of these logics, sentences denote quantum information quantities: systems of qubits (quregisters) or, more generally, mixtures of quregisters (qumixes), while logical connectives are interpreted as special quantum logical gates (which have a characteristic reversible and dynamic behavior). In this framework, states of knowledge may be entangled, in such a way that our information about the whole determines our information about the parts; and the procedure cannot be, generally, inverted. In spite of its appealing properties, the standard version of the quantum computational semantics is strongly “Hilbert-space dependent”. This certainly represents a shortcoming for all applications, where real and complex numbers do not generally play any significant role (as happens, for instance, in the case of natural and of artistic languages). We propose an abstract version of quantum computational semantics, where abstract qumixes, quregisters and registers are identified with some special objects (not necessarily living in a Hilbert space), while gates are reversible functions that transform qumixes into qumixes. In this framework, one can give an abstract definition of the notions of superposition and of entangled pieces of information, quite independently of any numerical values. We investigate three different forms of abstract holistic quantum computational logic.     

Quantum Circuit Synthesis using a New Quantum Logic Gate Library of NCV Quantum Gates

Since Controlled-Square-Root-of-NOT (CV, CV^?) gates are not permutative quantum gates, many existing methods cannot effectively synthesize optimal 3-qubit circuits directly using the NOT, CNOT, Controlled-Square-Root-of-NOT quantum gate library (NCV), and the key of effective methods is the mapping of NCV gates to four-valued quantum gates. Firstly, we use NCV gates to create the new quantum logic gate library, which can be directly used to get the solutions with smaller quantum costs efficiently. Further, we present a novel generic method which quickly and directly constructs this new optimal quantum logic gate library using CNOT and Controlled-Square-Root-of-NOT gates. Finally, we present several encouraging experiments using these new permutative gates, and give a careful analysis of the method, which introduces a new idea to quantum circuit synthesis.     

基于逻辑器件响应特性的自治布尔网络调控

自治布尔网络已成功应用于随机数产生、基因调控、储备池计算等领域.为了在应用中合理选择器件使输出更好地满足各应用的需求,本文研究了自治布尔网络中的逻辑器件响应特性变化时,自治布尔网络输出状态随之变化的规律,结果显示逻辑器件响应特性变化可以调控自治布尔网络输出在周期和混沌之间转变,且能改变自治布尔网络输出序列的复杂程度.进一步观察了逻辑器件响应特性和链路延时二维参数空间中输出序列复杂程度的分布,结果显示快的逻辑门响应特性可以增强高复杂序列在链路延时参数空间的分布范围.同时研究了自治布尔网络中任意逻辑器件的响应特性单独变化对网络输出状态的影响,结果显示不同节点的器件响应特性对序列复杂程度的调控能力有差异.研究表明,逻辑器件响应特性可以调控网络输出序列复杂程度,快的响应特性有利于高复杂混沌的稳定产生.     

Multiple-valued logic devices using single-electron circuits

Multiple-valued logic devices can be constructed compactly by utilizing quantized behavior of single-electron circuits. As an example, a single-electron multiple-valued Hopfield network solving optimization problems is designed. Computer simulation shows that the network can successfully converge to its optimal state that represents the solution to the problem.     

Theoretical design of single-molecule NOR and XNOR logic gates by using transition metal dibenzotetraaza[14]annulenes

The idea of replacing traditional silicon-based electronic components with the ones assembled by organic molecules to further scale down the electric circuits has been attracting extensive research focuses. Among the molecularly assembled components, the design of molecular logic gates with simple structure and high Boolean computing speed remains a great challenge. Here, by using the state-of-the-art nonequilibrium Green's function theory in conjugation with first-principles method, the spin transport properties of single-molecule junctions comprised of two serially connected transition metal dibenzotetraaza[14]annulenes(TM(DBTAA), TM = Fe, Co) sandwiched between two single-walled carbon nanotube electrodes are theoretically investigated. The numerical results show a close dependence of the spin-resolved current-voltage characteristics on spin configurations between the left and right molecular kernels and the kind of TM atom in TM(DBTAA)molecule. By taking advantage of spin degree of freedom of electrons, NOR or XNOR Boolean logic gates can be realized in Fe(DBTAA) and Co(DBTAA) junctions depending on the definitions of input and output signals. This work proposes a new kind of molecular logic gates and hence is helpful for further miniaturization of the electric circuits.     

Thermal logic gates: computation with phonons

Logic gates are basic digital elements for computers. We build up thermal logic gates that can perform similar operations as their electronic counterparts. The thermal logic gates are based on nonlinear lattices, which exhibit very intriguing phenomena due to their temperature dependent power spectra. We demonstrate that phonons, the heat carriers, can also be used to carry information and processed accordingly. The possibility of nanoscale experiments is discussed.     

Optimization Approaches for Designing a Novel 4-Bit Reversible Comparator

Reversible logic is a new rapidly developed research field in recent years, which has been receiving much attention for calculating with minimizing the energy consumption. This paper constructs a 4×4 new reversible gate called ZRQ gate to build quantum adder and subtraction. Meanwhile, a novel 1-bit reversible comparator by using the proposed ZRQC module on the basis of ZRQ gate is proposed as the minimum number of reversible gates and quantum costs. In addition, this paper presents a novel 4-bit reversible comparator based on the 1-bit reversible comparator. One of the vital important for optimizing reversible logic is to design reversible logic circuits with the minimum number of parameters. The proposed reversible comparators in this paper can obtain superiority in terms of the number of reversible gates, input constants, garbage outputs, unit delays and quantum costs compared with the existed circuits. Finally, MATLAB simulation software is used to test and verify the correctness of the proposed 4-bit reversible comparator.     

All optical logic gates based on cavity solitons with nonlinear gain

In this work we present a scheme based on the complementary behavior of the two effective parameters in Cavity Soliton switching process by which it is possible to design logic gates, namely “OR” and “AND”. By considering two independent writing beams, it is shown that by properly adjusting the amplitude and duration of switching pulses, “AND” and “OR” logical operations can be carried out. Specifically, the output of the system, which is the on or off state of the Cavity Soliton, is determined according to the inputs of the system which depend on the type of desired operation. The simulations show that these processes take place in a time scale of less than a nanosecond. The cascadibility of these gates is also studied.     

A scheme of developing frequency encoded tristate logic operations exploiting nonlinear character of PPLN waveguide and RSOA

In binary logic the information is represented by two distinct states only (0 and 1 state). The major disadvantage of the binary or Boolean logic operation is due to its limitation of large information handling capacity. It is established that tristate operations can be accommodated with optics in data processing, as this type of operation can enhance the operation speed very much as well as information capacity. Here in this communication the authors propose a new concept to implement all-optical different logic gates with tristate mechanism using frequency-encoding principle. For this purpose, co-propagating beams having different frequencies in C-band have used for generating cascaded sum and difference frequency, exploiting the nonlinear response character of periodically poled LiNbO₃ waveguide (PPLN). The highly reflecting property of optical add and drop multiplexer (ADM) and high wavelength conversion property of reflecting semiconductor optical amplifiers (RSOA) have been exploited here to implement the desired AND, NAND,OR and NOR logic operations with tristate. As NAND and NOR are the universal logic operation, so any other member of this logic family may be implemented with these.     

All-Optical Multifunctional Logic Gates for Image Information Using Photorefractive Two-Wave Mixing

In this paper, we propose all-optical multifunctional logic gates for image information using photorefractive (PR) two-wave mixing. The optical setup is simply configured compared with the other all-optical logic gates for image information. The XOR-, OR-, and AND-operation are all-optically performed in the same optical setup through the transitional response of the PR medium. One can switch these logic operations simply by means of the on-off control of the signal and the pump beam illumination. We analyze the spatial distribution of beam intensity in these logic gates using a finite-difference beam propagation method (FD-BPM) and the crosstalk between adjoining pixels is examined from the result. We also experimentally verify that the XOR-, OR-, and AND-gates are realized in the same optical setup.     

细菌视紫红质在全光逻辑器件中的研究与应用

介绍了细菌视紫红质在逻辑器件中的研究与应用,总结了利用细菌视紫红质研究逻辑器件的方法,明确进一步研究逻辑器件的发展方向是智能化器件的开发.     

Electrical joule heating for the isolation of ZnO nanowire channel and subsequent high-performance 1D circuit integration

In this work, electrical Joule heating (J-H) was employed for the first time to electrically isolate ZnO nanowire FETs array for one dimensional (1D) logic applications without any physical and electrical damages. The electrical properties of the isolated nanowire FETs were found to be superior to non-isolated FETs came from the neighboring gate effect. Finally, we investigated ZnO nanowire-based NOT, NAND, and NOR logic gates with the J-H nanowire isolation technique. The isolated logic gates clearly show much lower output voltage off level than the non-isolated circuits thus resulting in more accurate and reliable 1D electronic applications.     

Quantum Fourier Transform-Based Arithmetic Logic Unit on a Quantum Processor

This study proposes and construct a primitive quantum arithmetic logic unit (qALU) based on the quantum Fourier transform (QFT). The qALU is capable of performing arithmetic ADD (addition) and logic NAND gate operations. It designs a scalable quantum circuit and presents the circuits for driving ADD and NAND operations on two-input and four-input quantum channels, respectively. By comparing the required number of quantum gates for serial and parallel architectures in executing arithmetic addition, it evaluates the performance. It also execute the proposed quantum Fourier transform-based qALU design on real quantum processor hardware provided by IBM. The results demonstrate that the proposed circuit can perform arithmetic and logic operations with a high success rate. Furthermore, it discusses in detail the potential implementations of the qALU circuit in the field of computer science, highlighting the possibility of constructing a soft-core processor on a quantum processing unit.     

Dislocation Coupling-Induced Transition of Synchronization in Two-Layer Neuronal Networks

The mutual coupling between neurons in a realistic neuronal system is much complex, and a two-layer neuronal network is designed to investigate the transition of electric activities of neurons. The Hindmarsh-Rose neuron model is used to describe the local dynamics of each neuron, and neurons in the two-layer networks are coupled in dislocated type. The coupling intensity between two-layer networks, and the coupling ratio (Pro), which defines the percentage involved in the coupling in each layer, are changed to observe the synchronization transition of collective behaviors in the two-layer networks. It is found that the two-layer networks of neurons becomes synchronized with increasing the coupling intensity and coupling ratio (Pro) beyond certain thresholds. An ordered wave in the first layer is useful to wake up the rest state in the second layer, or suppress the spatiotemporal state in the second layer under coupling by generating target wave or spiral waves. And the scheme of dislocation coupling can be used to suppress spatiotemporal chaos and excite quiescent neurons.     

Realization of Quantum Circuits in Fock Space

In this letter, by using the method we offered in our paper [L. Ma and Y.D. Zhang, Commun. Theor. Phys. (Beijing, China) 36 (2001) 119], some extended quantum logic gates, such as quantum counter, quantum adder, are studied and their expressions are given. It may be useful for us to study the more complicated quantum logic circuits deeply.     

Ultrafast digital soliton logic gates

We demonstrate all-optical fibre switches, including soliton-dragging logic gates, soliton-interaction gates and soliton-trapping AND-gates, that have the potential of operating up to speeds of 0.2 Tbps. Solitons in fibres are attractive for ultrafast timedomain switching because they avoid pulse distortion during propagation and because they exhibit particle-like properties. Soliton-dragging logic gates satisfy all requirements for a digital optical processor and having switching energies approaching 1 pJ. In addition, soliton-dragging logic gates are one example of a more general timedomain chirp switch architecture in which a dispersive delay line acts as a lever-arm to reduce the switching energy. Soliton-interaction gates are based on elastic collisions between solitons and illustrate that solitons can be used to implement conservative, billiard-ball logic operations. Soliton-trapping AND-gates are sensitive to the timing of the input pulses and display on/off contrast ratios greater than 201. The soliton-trapping AND-gate can serve as the final stage in an all-optical system and as the interface to electronics. These ultrafast gates may prove advantageous in applications where the switch bandwidth limits the performance of the system