共查询到20条相似文献,搜索用时 31 毫秒
1.
A novel Josephson complementary ternary logic (JCTL) circuit is described. This fundamental circuit is based on the combination of two SQUIDs (superconducting quantum interference devices), one of which is switched in the positive direction and the other in the negative direction. The JCTL can perform the fundamental operations of AND, OR, NOT, and Double NOT in ternary form. The principle of the operation and design criteria are described in detail. Simulation results show that reliable operation of these circuits can be achieved with a high performance 相似文献
2.
Gate‐Controlled BP–WSe2 Heterojunction Diode for Logic Rectifiers and Logic Optoelectronics
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dong Li Biao Wang Mingyuan Chen Jun Zhou Zengxing Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(21)
p–n junctions play an important role in modern semiconductor electronics and optoelectronics, and field‐effect transistors are often used for logic circuits. Here, gate‐controlled logic rectifiers and logic optoelectronic devices based on stacked black phosphorus (BP) and tungsten diselenide (WSe2) heterojunctions are reported. The gate‐tunable ambipolar charge carriers in BP and WSe2 enable a flexible, dynamic, and wide modulation on the heterojunctions as isotype (p–p and n–n) and anisotype (p–n) diodes, which exhibit disparate rectifying and photovoltaic properties. Based on such characteristics, it is demonstrated that BP–WSe2 heterojunction diodes can be developed for high‐performance logic rectifiers and logic optoelectronic devices. Logic optoelectronic devices can convert a light signal to an electric one by applied gate voltages. This work should be helpful to expand the applications of 2D crystals. 相似文献
3.
A logic scheme using Josephson tunnel junctions in a current-steering mode is described. Switching from voltageV = 0 toV neq 0 is accomplished by adding a fraction of the control-line currents to the bias current. In one form the addition is accomplished by shunting the junction to be switched with a loop containing a second junction serving a diode-like function and causing one or more control lines to possess inductive coupling to the loop. A five-element circuit demonstrating AND, OR and INVERSION operations carried out by this approach has been fabricated and works as expected. 相似文献
4.
The authors describe a three-valued content-addressable memory cell using a Josephson complementary ternary logic (JCTL) circuit. The memory cell can perform the operations of searching, writing and reading in the ternary logic system. The principle of the memory circuit is illustrated in detail by using the threshold characteristics of the JCTL. Computer simulations were performed to investigate how high-performance operation can be achieved. Simulation results show that the cycle time of memory operation is 120 ps, power consumption is about 0.5 μW/cell, and tolerances of writing and reading operation are ±15% and ±24% respectively 相似文献
5.
C. J. Lehner D. E. Oates Y. M. Habib G. Dresselhaus M. S. Dresselhaus 《Journal of Superconductivity》1999,12(2):363-376
A circuit model is presented for Josephson junctions (JJs) that solves the nonlinear long-junction equation, driven by a nonuniform current distribution. This extended resistively shunted junction (ERSJ) model consists of a parallel array of ideal resistively shunted JJs coupled by inductors. The junction array is connected to an array of current sources that simulate the time- and space-dependent current distribution in a stripline. The rf-current dependent complex impedance of a long JJ calculated using this model agrees with measured data on a YBCO grain-boundary JJ and provides an explanation of the measured steps in the resistance resulting from the creation, annihilation, and motion of Josephson vortices under the influence of rf currents. This model contributes to a better understanding of the power-handling characteristics of high-T
c microwave devices, in which the power losses are believed to result from JJ effects associated with imperfections in the films. The model also predicts second-harmonic generation with a highly nonlinear and nonmonotonic power dependence. Details of the dynamics of Josephson vortices are presented and discussed. 相似文献
6.
Kosaka S. Shoji A. Aoyagi M. Shinoki F. Tahara S. Ohigashi H. Nakagawa H. Takada S. Hayakawa H. 《IEEE transactions on magnetics》1985,21(2):102-109
An integration process for the fabrication of an all refractory Josephson LSI logic circuit is described. In this process, niobium nitride and niobium double-layered Josephson junctions were integrated using a reactive ion etching with a 2.5 μm minimum feature. A highly selective and anisotropic RIE process and a planarizing technology have been developed for intagrating a circuit with LSI complexity. For evaluating the process capability, test vehicle circuits with MSI/LSI level complexity have been designed and fabricated using this process. An 8 bit ripple carry adder and a 4×4 bit parallel multiplier have been integrated with Josephson four junction logic ( 4JL ) gates, the largest of which contains more than 2800 Josephson junctions. Both functionality and high-speed performance testings have been successfully performed with these test circuits. 相似文献
7.
This paper examines the feasibility and potential for applications of intimately combining semiconductor and superconductor devices at circuit and system levels. The focus is mainly on the temperature range 27–77 K. One of the main issues is the heat produced by the semiconductor devices, since the superconductor devices produce much less heat and are sensitive to temperature changes. It is shown that Josephson junctions made with high temperature superconductors can be placed very close to transistors on a properly heatsunk chip. A second important issue is interfacing the low voltages of superconducting devices to the much higher voltages needed for transistors; an existing technique is discussed in the context of high temperature superconductors. Only well developed semiconductor technologies have been considered; although there is some possibility of making low voltage transistors, this is not explored here. The paper concludes with an analysis of the various applications that can be realized, depending on the type of device available in high temperature superconductor technology: passive patterned films, nonhysteretic Josephson devices or Josephson tunnel juntions. 相似文献
8.
A quantum-flux-type logic circuit is proposed which is composed of Josephson junction transmission lines, along which localized magnetic flux can propagate. By choosing bias current properly, the duplication of magnetic flux and a variety of logical functions can be obtained without changing the circuit topology. Computer simulation results are presented on AND and OR operations with two and three inputs for the same circuit topology, confirming that these circuits can be used as logic circuits. The simulations demonstrate the high-speed operation and low power consumption of this circuit 相似文献
9.
Indian logic has a long history. It somewhat covers the domains of two of the six schools (darsanas) of Indian philosophy, namely,Nyaya andVaisesika. The generally accepted definition of Indian logic over the ages is the science which ascertains valid knowledge either by
means of six senses or by means of the five members of the syllogism. In other words, perception and inference constitute
the subject matter of logic. The science of logic evolved in India through three ages: the ancient, the medieval and the modern,
spanning almost thirty centuries. Advances in Computer Science, in particular, in Artificial Intelligence have got researchers
in these areas interested in the basic problems of language, logic and cognition in the past three decades. In the 1980s,
Artificial Intelligence has evolved into knowledge-based and intelligent system design, and the knowledge base and inference
engine have become standard subsystems of an intelligent system. One of the important issues in the design of such systems
is knowledge acquisition from humans who are experts in a branch of learning (such as medicine or law) and transferring that
knowledge to a computing system. The second important issue in such systems is the validation of the knowledge base of the
system i.e. ensuring that the knowledge is complete and consistent. It is in this context that comparative study of Indian
logic with recent theories of logic, language and knowledge engineering will help the computer scientist understand the deeper
implications of the terms and concepts he is currently using and attempting to develop. 相似文献
10.
Kosaka S. Nakagawa H. Kawamura H. Okada Y. Hamazaki Y. Aoyagi M. Kurosawa I. Shoji A. Takada S. 《IEEE transactions on magnetics》1989,25(2):789-794
The authors describe the design and operation of a Josephson address control unit IC (integrated circuit), which will be used for controlling the instruction sequence of an experimental 4-bit Josephson microcomputer prototype system. The IC is composed of three sets of 7- to 10-bit-wide registers and combinational logic circuits driven by a two-phase monopolar power supply. 593 four-function logic gates have been used in the circuit and fabricated using 2.5-μm NbN/oxide/NbN junction technology with Mo resistors and SiO2 insulation. The operation of the circuit has been successfully tested for all the instructions which control the program sequence of the computer system 相似文献
11.
Josephson devices are potential elements for ultra-fast computers. Rather complex logic and memory circuits have been realized. Here quantum interference devices with improved speed and power performance are discussed. Latching and non-latching logic operation is possible and experiments with non-latching circuits are reviewed. Memory applications of quantum interference devices are also considered. 相似文献
12.
《IEEE transactions on magnetics》1989,25(2)
The following topics are dealt with: superconducting electronics; superconducting quantum interference devices (SQUIDs); magnetometers; Josephson device memories; thin-film superconducting materials; tunnel junctions; Josephson device logic circuits; high-T c (critical temperature) superconductors; YBaCuO superconductors: ceramic superconductor memories; millimeter-wave detectors; Josephson device mixers; superconducting transmission-line structure; superconducting microwave cavities; tunnel spectroscopy; laser-induced switching of superconductors; gradiometers; harmonic mixing; SIS (superconductor-insulator-superconductor) mixers; superconducting bolometers; superconductor device fabrication; SSC; (Superconductor Super Collider); magnets; superconducting magnets; chaos in Josephson junction systems; superconducting coils; superconducting material preparation; MHD; (magnetohydrodynamics) magnets; magnetic resonance imaging (MRI) magnets; and niobium materials devices 相似文献
13.
This paper describes a new Josephson device with microwave integrated circuit for voltage standard. The circuit is essentially made of a resonator (Nb), the Josephson junction (Nb, NbOx, Pb-In) and a capacitive microstrip section (Pb-In) which ends the rf part; the dc connections are through Cauer Filters (Nb or Pb-In). A niobium film is deposited on the opposite side of the fused quartz substrate as a ground plane. The circuit is enclosed in a special package with outside dc and rf connections. The technology ensures very good cyclability and lifetime with storage at room temperature. In liquid helium (4.2 K) with a very weak rf power less than 0.5 milliwatts at the frequency resonance (11.5 GHz), 100 μ A high current steps were obtained near a polarization of 4.5 mV. These devices allows a precision of 1 × 10?7 on the volt standard when used with a series-parallel divider of fixed value (ratio 225). The precise adjustment of the voltages is made by a slight drift of the rf frequency of the source, allowed by the high rf coupling factor of the device and the band width of its resonance. 相似文献
14.
Charles M. Jackson June H. Kobayashi Emery B. Guillory Claire Pettiette-Hall John F. Burch 《Journal of Superconductivity》1992,5(4):417-422
We describe a monolithic high-temperature superconductor (HTS) phase shifter based on the distributed Josephson inductance (DJI) design integrated monolithically into a 10-GHz microstrip line. This microwave circuit incorporates >1000 HTS rf SQUIDS. Recent data demonstrate the performance of this broadband HTS circuit. We observed phase shifts greater than 150° in resonant structures, and 20° in broadband circuits. The nonlinear inductance of the superconducting transmission line can be used for other novel applications, including parametric amplification. A comparison of the DJI circuit to a series array of Josephson elements (used for pulse sharpening) will contrast these two new and exciting nonlinear transmission line circuits. 相似文献
15.
Integrated circuit chips were designed and fabricated, based on a Josephson shift register circuit that simulated operation at 25 GHz using the SPICE program. The 6.25-mm2 chip featured a twelve-gate, four-stage shift register fabricated with Nb/AlOx/Nb Josephson junctions with a design value of 2000 A/cm2 critical current density. SUPERCOMPACT, a general program for the design of monolithic microwave integrated circuits, was used to model the effects of layout geometry on the uniformity and phase coherence of logic gate bias currents. A layout geometry for the superconductive transmission lines and thin-film bias resistors was developed. The original SPICE-designed circuit was modified as a result of these calculations. Modeling indicated that bias current variations could be limited to 3% for all possible logic states of the shift register, and phase coherence of the gates could be maintained to within 2° at 10 GHz. The fundamental soundness of the circuit design was demonstrated by the proper operation of fabricated shift registers 相似文献
16.
17.
C. J. Lehner D. E. Oates Y. M. Habib G. Dresselhaus M. S. Dresselhaus 《Journal of Superconductivity and Novel Magnetism》1999,12(2):363-376
A circuit model is presented for Josephson junctions (JJs) that solves the nonlinear long-junction equation, driven by a nonuniform current distribution. This extended resistively shunted junction (ERSJ) model consists of a parallel array of ideal resistively shunted JJs coupled by inductors. The junction array is connected to an array of current sources that simulate the time- and space-dependent current distribution in a stripline. The rf-current dependent complex impedance of a long JJ calculated using this model agrees with measured data on a YBCO grain-boundary JJ and provides an explanation of the measured steps in the resistance resulting from the creation, annihilation, and motion of Josephson vortices under the influence of rf currents. This model contributes to a better understanding of the power-handling characteristics of high-T c microwave devices, in which the power losses are believed to result from JJ effects associated with imperfections in the films. The model also predicts second-harmonic generation with a highly nonlinear and nonmonotonic power dependence. Details of the dynamics of Josephson vortices are presented and discussed. 相似文献
18.
19.
This paper presents the latest design work of high speed adder logic based on Josephson elements. The Josephson adder uses a novel exclusive-OR logic and performs high speed carry propagation technique. The idea of directionality is also undertaken to avoid the necessary distortion in carry signal. The principle of operation with salient feature of simulation of the adder are presented in full detail. Necessary checks for carry skip and other fabrication parameters are investigated using detailed model of the device based on its highly miniaturized size. The results of the simulation show that the nominal delay of the adder logic is 20 ps/stage and average power dissipation is 47 μW/stage. Authors have mainly stressed upon how to obtain ultra fast speed at the cost of very low power dissipation of the presented adder with its small size. 相似文献
20.
The re-entrant flow shop scheduling problem considering time windows constraint is one of the most important problems in hard-disc drive (HDD) manufacturing systems. In order to maximise the system throughput, the problem of minimising the makespan with zero loss is considered. In this paper, evolutionary techniques are proposed to solve the complex re-entrant scheduling problem with time windows constraint in manufacturing HDD devices with lot size. This problem can be formulated as a deterministic Fm?|?fmls, rcrc, temp?|?Cmax problem. A hybrid genetic algorithm was used for constructing chromosomes by checking and repairing time window constraints, and improving chromosomes by a left-shift heuristic as a local search algorithm. An adaptive hybrid genetic algorithm was eventually developed to solve this problem by using fuzzy logic control in order to enhance the search ability of the genetic algorithm. Finally, numerical experiments were carried out to demonstrate the efficiency of the developed approaches. 相似文献