Asynchronous Dynamic Single-Flux Quantum Majority Gates Gleb Krylov , Student Member, IEEE, and Eby G

Total Page:16

File Type:pdf, Size:1020Kb

Asynchronous Dynamic Single-Flux Quantum Majority Gates Gleb Krylov , Student Member, IEEE, and Eby G IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 30, NO. 5, AUGUST 2020 1300907 Asynchronous Dynamic Single-Flux Quantum Majority Gates Gleb Krylov , Student Member, IEEE, and Eby G. Friedman , Fellow, IEEE Abstract—Among the major issues in modern large-scale rapid of an SFQ pulse within a clock period. In logic gates, the single-flux quantum (RSFQ) circuits are the complexity of the input pulses are processed by switching Josephson junctions clock network, tight timing tolerances, poor applicability of (JJs), and an output pulse is produced based on the target existing CMOS-based design algorithms, and extremely deep pipelines, which reduce the effective clock frequency. In this logic function. Most RSFQ logic gates require a clock signal article, asynchronous dynamic single-flux quantum majority gates either to release the output pulse or to reinitialize the state are proposed to solve some of these problems. The proposed logic of the gate to process the next datum. A large scale circuit gates exhibit high bias margins and do not require significant area utilizing these gates requires a complex clock network. RSFQ or a large number of Josephson junctions as compared to existing circuits are capable of operating at extremely high clock fre- RSFQ logic gates. These gates exhibit a tradeoff among the input skew tolerance, clock frequency, and bias margins. Asynchronous quencies (up to hundreds of gigahertz [8]), resulting in narrow logic gates greatly reduce the complexity of the clock network timing tolerances. in large-scale RSFQ circuits, thereby alleviating certain timing Multiple synchronization approaches exist for reducing the issues and reducing the required bias currents. Furthermore, effects of timing on circuit operation. These approaches asynchronous logic allows existing design algorithms to utilize range from globally asynchronous locally synchronous tech- CMOS approaches for synthesis, verification, and testability. The adoption of majority logic in complex RSFQ circuits also reduces niques [9], [10] to fully asynchronous structures [11], [12] and the pipeline depth, enabling higher clock speeds in very large scale dual rail logic families [13]. These approaches, however, intro- integration RSFQ circuits. duce significant performance and area overhead as compared to Index Terms—Single-flux quantum (SFQ), superconductive conventional synchronous RSFQ circuits, partially negating the digital electronics, superconductive integrated circuits. primary incentives of RSFQ technology. Another distinctive feature that adversely affects the increas- I. INTRODUCTION ing integration of RSFQ circuits is limited fanout. Typical RSFQ logic gates and flip flops exhibit a fanout of one. A splitter HE slowdown in scaling of CMOS technology has led gate is used to deliver a signal to multiple inputs. This property T to increasing interest in beyond CMOS computing tech- necessitates large splitter trees that can dominate the area of nologies, including cryogenic and superconductive electronics. a complex circuit. Insertion of these splitter trees into a logic Rapid single-flux quantum (RSFQ) [1] is a well established and path increases the delay of the path, significantly reducing the widely used logic family in superconductive electronics [2]. The effective clock frequency of the overall system—degrading a increased interest [3] combined with recent advances in fabri- primary advantage of RSFQ circuits. RSFQ clock networks cation technology for single-flux quantum (SFQ) circuits [4] consist mostly of splitters, decreasing the area available for logic. provides enhanced complexity while requiring novel design Novel solutions are, therefore, necessary to either support larger algorithms, methodologies, and tools specifically targeting large fanout or to reduce the number of splitters. scale RSFQ circuits [5], [6]. Existing RSFQ circuits typically utilize AND/OR/NOT logic Distribution of the clock signals in very large scale integration with clocked AND and OR gates and, therefore, exhibit these (VLSI) RSFQ circuits is an important issue [7]. A distinctive aforementioned issues. An alternative functionally complete feature of RSFQ circuits is clocked logic gates. In SFQ tech- logic set is the MAJ/INV set, consisting of majority gates and nology, the data are represented by the presence or absence inverters. Logic synthesis utilizing MAJ/INV logic has been shown to reduce logic depth, power, and delay in both CMOS Manuscript received August 7, 2019; revised November 8, 2019; accepted benchmarks [14] and beyond CMOS technologies [15]. January 14, 2020. Date of publication March 4, 2020; date of current ver- No efficient RSFQ majority gate has currently been described sion May 5, 2020. This work was supported by the Department of Defense Agency—Intelligence Advanced Research Projects Activity through the U.S. in the literature. A majority gate is typically composed of a Army Research Office under Contract W911NF-17-9-0001. This paper was combination of AND/OR/NOT gates and requires a clock signal recommended by Associate Editor H. Rogalla. (Corresponding author: Gleb with a network of multiple splitters. This topology, therefore, Krylov.) The authors are with the Department of Electrical and Computer En- exhibits a large overhead both in area and delay and is, therefore, gineering, University of Rochester, Rochester, NY 14627 USA (e-mail: infeasible in complex circuits. In other SFQ logic families, such [email protected]; [email protected]). as quantum flux parametron (QFP) [16] and reciprocal quantum Color versions of one or more of the figures in this article are available online at http://ieeexplore.ieee.org. logic [17], majority gates exist and are widely used [18], [19]. Digital Object Identifier 10.1109/TASC.2020.2978428 1051-8223 © 2020 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See https://www.ieee.org/publications/rights/index.html for more information. Authorized licensed use limited to: UNIVERSITY OF ROCHESTER. Downloaded on November 13,2020 at 23:35:30 UTC from IEEE Xplore. Restrictions apply. 1300907 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 30, NO. 5, AUGUST 2020 Fig. 1. DSFQ storage loops. (a) Traditional dynamic loop. (b) Novel dynamic loop introduced in [20]. Fig. 2. Loop current (a) within a loop with a single time constant (dashed line) and (b) within a loop with dual time constants (solid line). In this article, novel asynchronous RSFQ majority gates are proposed based on a recently introduced dynamic SFQ (DSFQ) Self-resetting storage loops have been used for many years logic family [20]. In Section II, a discussion of DSFQ is pro- and utilize either resistors or overdamped JJs inserted within the vided, and the benefits of DSFQ storage loops are discussed. loops for flux leakage [21]–[23]. These loops exhibit a narrow In Section III, circuit design issues and related parameters for timing tolerance due to a nearly constant rate of flux leakage, DSFQ loops are discussed. In Section IV, majority gates are controlled by a single time constant. An example of this type of introduced, the operation of these gates is described, and margin dynamic loop is shown in Fig. 1(a). A recently introduced DSFQ characteristics are presented. In Section V, the application of storage loop [20], shown in Fig. 1(b), utilizes a critically damped majority gates to VLSI RSFQ circuits is discussed. Finally, JJ in parallel with a JJ in series with a resistor to reset the state. Section VI concludes this article. This topology produces two different time constants, for hold and reset, combining the slow leakage process during the hold period with fast relaxation to the initial state. A comparison of II. DSFQ STORAGE LOOPS the current stored within a dynamic loop with single and double A novel family of asynchronous RSFQ logic gates—DSFQ time constants, exhibiting a twofold increase in hold time, is gates—is discussed in this section. DSFQ [20] is a recently shown in Fig. 2. introduced type of RSFQ logic, where the state of a gate is Novel DSFQ logic gates [20] combine the self-resetting stor- temporarily stored, and the gate self-resets to the initial state age loops with existing RSFQ circuits to achieve AND and OR after a period of time. This capability enables asynchronous logic functions. As the inversion operations can be propagated operation, significantly reducing the size and energy require- to the boundary of the combinatorial logic clouds [24] and ments of complex clock networks in large scale RSFQ circuits. integrated into registers with complementary outputs, these gates DSFQ circuits are more similar to CMOS than regular RSFQ produce a functionally complete set. circuits and can be separated into sequential and combinatorial In the following section, operation of DSFQ storage loops is logic [20], enabling the use of relevant CMOS design techniques described. The effects of different circuit parameters are also and algorithms. discussed. The primary features of DSFQ are self-resetting storage loops, as shown in Fig. 1. In conventional RSFQ, logic gates contain III. CIRCUIT DESIGN OF DYNAMIC LOOPS storage loops, which temporarily store a state based upon the input pulses received by the gate. The state of these storage In this section, the operation and circuit components of DSFQ loops is typically reset by either the clock pulse (e.g., DFF) or loops are described. The effects of these components on the by another input pulse (e.g., Muller C element). In the absence operation of the logic gate are discussed, and guidelines for of a reset pulse, logic gates can store a state indefinitely. This these parameters are provided. capability greatly complicates the application of certain CMOS DSFQ storage loops require a leakage mechanism for the techniques to RSFQ circuits and exacerbates flux trapping ef- magnetic flux to escape a superconductive loop. In the DSFQ fects, while increasing the complexity of the clock network. loop shown in Fig. 1(b), a combination of JJs and resistors is Authorized licensed use limited to: UNIVERSITY OF ROCHESTER. Downloaded on November 13,2020 at 23:35:30 UTC from IEEE Xplore.
Recommended publications
  • Adiabatic Quantum-Flux-Parametron with Delay-Line Clocking: Logic Gate Demonstration and Phase Skipping Operation
    Adiabatic quantum-flux-parametron with delay-line clocking: logic gate demonstration and phase skipping operation Taiki Yamae,1,2 Naoki Takeuchi,3,4,* and Nobuyuki Yoshikawa1,4 1 Department of Electrical and Computer Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan 2 Research Fellow of Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda, Tokyo 102-0083, Japan 3 Research Center for Emerging Computing Technologies, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba 305-8568, Japan 4 Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan * [email protected] Abstract. Adiabatic quantum-flux-parametron (AQFP) logic is an energy-efficient superconductor logic family. The latency of AQFP circuits is relatively long compared to that of other superconductor logic families and thus such circuits require low-latency clocking schemes. In a previous study, we proposed a low-latency clocking scheme called delay-line clocking, in which the latency for each logic operation is determined by the propagation delay of the excitation current, and demonstrated a simple AQFP buffer chain that adopts delay-line clocking. However, it is unclear whether more complex AQFP circuits can adopt delay-line clocking. In the present study, we demonstrate AQFP logic gates (AND and XOR gates) that use delay-line clocking as a step towards implementing large-scale AQFP circuits with delay-line clocking. 1 AND and XOR gates with a latency of approximately 20 ps per gate are shown to operate at up to 5 and 4 GHz, respectively, in experiments.
    [Show full text]
  • Reversible Logic Gate Using Adiabatic Superconducting Devices and Experimentally Demonstrate the Logical 15 September 2014 and Physical Reversibility of the Gate
    OPEN Reversible logic gate using adiabatic SUBJECT AREAS: superconducting devices APPLIED PHYSICS N. Takeuchi, Y. Yamanashi & N. Yoshikawa ELECTRICAL AND ELECTRONIC ENGINEERING Department of Electrical and Computer Engineering, Yokohama National University, Hodogaya, Yokohama 240-8501, Japan. COMPUTER SCIENCE Reversible computing has been studied since Rolf Landauer advanced the argument that has come to be Received known as Landauer’s principle. This principle states that there is no minimum energy dissipation for logic 17 June 2014 operations in reversible computing, because it is not accompanied by reductions in information entropy. Accepted However, until now, no practical reversible logic gates have been demonstrated. One of the problems is that reversible logic gates must be built by using extremely energy-efficient logic devices. Another difficulty is 26 August 2014 that reversible logic gates must be both logically and physically reversible. Here we propose the first practical Published reversible logic gate using adiabatic superconducting devices and experimentally demonstrate the logical 15 September 2014 and physical reversibility of the gate. Additionally, we estimate the energy dissipation of the gate, and discuss the minimum energy dissipation required for reversible logic operations. It is expected that the results of this study will enable reversible computing to move from the theoretical stage into practical usage. Correspondence and requests for materials nergy efficiency has become the most important metric of advancement in modern computer design1,2. One should be addressed to of the most well-known theories regarding the fundamental energy limits in computation is Landauer’s principle3, where Rolf Landauer predicted that the erasure of 1-bit information generates heat of more than N.T.
    [Show full text]
  • Japanese Semiconductor Industry Service
    Japanese Semiconductor Industry Service Volume II Technology & Government Dataquest nn a company of The Dun & Bradstreet Corporation 1290 Ridder Park Drive San Jose, California 95131-2398 (408) 437-8000 Telex: 171973 Fax: (408) 437-0292 Sales/Service offices: UNITED KINGDOM GERMANY Dataquest UK Limited Dataquest GmbH 13th Floor, Centrepoint Rosenkavalierplatz 17 103 New Oxford Street D-8000 Munich 81 London WCIA IDD West Germany England (089)91 10 64 01-379-6257 Telex: 5218070 Telex: 266195 Fax: (089)91 21 89 Fax: 01-240-3653 FRANCE JAPAN Dataquest SARL Dataquest Japan, Ltd. 100, avenue Charles de Gaulle Taiyo Ginza Building/2nd Floor 92200 Neuilly-sur-Seine 7-14-16 Ginza, Chuo-ku France Tokyo 104 Japan (01)4738.13.12 (03)546-3191 Telex: 611982 Telex: 32768 Fax: (01)4738.11.23 Fax: (03)546-3198 The content of this report represents our interpretation and analysis of information generally available to the public or released by responsible individuals in the subject com­ panies, but is not guaranteed as to accuracy or completeness. It does not contain material provided to us in confidence by our clients. This information is not furnished in connection with a sale or offer to sell securities, or in connection with the solicitation of an offer to buy securities. This firm and its par­ ent and/or their officers, stockholders, or members of their families may, from time to time, have a long or short position in the securities mentioned and may sell or buy such securities. Printed in the United States of America. All rights reserved.
    [Show full text]
  • 1988 DE88 013629 Applied Superconductfertty Uofiioffwico Sheraton-Pataca How San Francisco, CA August 21-25,190$
    CONF-880812— Absts. 1988 DE88 013629 Applied Superconductfertty UOfiiOffWiCO Sheraton-Pataca HoW San Francisco, CA August 21-25,190$ Sponsors Lawrence Livermore National Laboratory University of California Department of Energy Office of Fusion Energy and Division of High Energy Physics Bechtel National, Inc. Teledyne Wah Chang -dm Contents Conference Schedule iv P-3 Plenary HI Map of Conference Center v Materials 48 Session El SQUID Applications 48 P-1 Plenary I ML High Tc Superconductors: High-Speed Josephson Integrated Oxygen Ordering 49 Circuit Technology 1 LI Stability II 50 EA Superconducting Integrated Circuits .... 1 EJ 3 Terminal Devices/IC Processing II .... 51 MA NbTi Processing and Properties 4 MM High Tc Superconductors: LA SSC 5 Miscellaneous Properties 53 EB High Tc Superconductor Electronics I ... 6 LJ Fusion Ill/MHD II 55 MB NbTi: Measurements and AC Losses ... 7 EK High Tc Superconductor Electronics II... 56 LB Fusion I 8 MN High Tc Superconductors: EC Digital Applications 9 Critical Currents II 57 MC NbN, Nb3AI, and Nb3Sn 13 LK Medical Applications 57 LC Stability I 14 EL Particle and IR Detectors 58 MD High Tc Superconductors: MO High Tc Superconductors: Bulk Processing i 16 Characterization 60 ME High Tc Superconductors: LL Energy Storage, Generation, Measurements 17 and Switching 62 LD Fusion II/MHD I 18 MP Nb3Sn: Measurements 63 ED Miscellaneous High Tc MQ High Tc Superconductors: Superconductor Electronics 19 High-Frequency Responses 64 P-2 Plenary II P-4 Plenary IV SMES 26 CEBAF 66 EE Noise in SQUIDs 26 EM Millimeter Wave Technology II 66 MF NbN and Nb3AI 27 MR High Tc Superconductors: LE SMES I 29 Thin Films II 67 EF Millimeter Wave Technoiogy I 30 LM Conductor Testing 68 MG NbTi: AC Losses and Stability 32 EN Josephson Junction Dynamics 69 LF SSC II 34 MS High Tc Superconductors: EG Device Processing 35 Thin Films III 71 MH High Tc Superconductors: LN Magnet Technology 74 Critical Currents I 37 MT High Tc Superconductors: LG SMES II 38 Magnetic Properties and Applications ..
    [Show full text]
  • Demonstration of Signal Transmission Between Adiabatic Quantum-Flux-Parametrons and Rapid Single-Flux-Quantum Circuits Using Superconductive Microstrip Lines
    Demonstration of Signal Transmission between Adiabatic Quantum-Flux-Parametrons and Rapid Single-Flux-Quantum Circuits Using Superconductive Microstrip Lines F. China, N. Tsuji, T. Narama, N. Takeuchi, T. Ortlepp, Y. Yamanashi, Member, IEEE, and N. Yoshikawa, Member, IEEE [8-10] are optimized to obtain a fully adiabatic operation mode. Abstract—We have been investigating interface circuits The power consumption of AQFP logic is estimated to be three between rapid single-flux-quantum (RSFQ) circuits and adiabatic orders of magnitude lower than that of RSFQ logic [11]. In quantum-flux-parametron (AQFP) circuits for use in high-speed, general, AQFP gates can operate with small input currents, low-power hybrid computing system. These interface circuits also which enables fairly long direct interconnections between them. enable us to use long-distance interconnections between AQFP gates. In this study, we fabricated and demonstrated AQFP However, the maximum length of the interconnections is circuits, including long interconnections of passive transmission limited to approximately 1 mm due to circuit parameter lines (PTLs), in which the interface circuits were used to convert deviations [12], [13]. the signal currents of the AQFP gates into single-flux-quantum In a previous study [14], we investigated interface circuits (SFQ) pulses traveling along PTLs. The length of each PTL was between RSFQ circuits and AQFP gates with the aim of approximately 4.3 mm. During low-speed measurements, correct constructing an RSFQ/AQFP hybrid computer system. operations with wide bias margins were confirmed. Moreover, these interface circuits enable us to use Index Terms—RSFQ, AQFP, passive transmission line, long-distance interconnections based on passive transmission interface, superconducting integrated circuit lines (PTLs) [15], [16] between AQFP gates.
    [Show full text]
  • Synthesis Flow for Cell-Based Adiabatic Quantum-Flux-Parametron Structural Circuit Generation with HDL Backend Verification Qiuyun Xu, Christopher L
    1 Synthesis Flow for Cell-Based Adiabatic Quantum-Flux-Parametron Structural Circuit Generation with HDL Backend Verification Qiuyun Xu, Christopher L. Ayala, Member, IEEE, Naoki Takeuchi, Member, IEEE, Yuki Murai, Yuki Yamanashi, Member, IEEE, and Nobuyuki Yoshikawa, Member, IEEE Abstract—Adiabatic quantum-flux-parametron (AQFP) is a very energy-efficient superconductor logic. In AQFP logic, dy- namic energy dissipation can be drastically reduced due to adi- abatic switching operations using ac excitation currents. During the past few years, AQFP logic family has been investigated and implemented. Experimental results prove the robustness of building large-scale integrated AQFP circuits. In this paper, an AQFP VLSI design flow is introduced and detailed with a 16-bit decoder as example circuit. By including logic synthesis and automatic routing tools, this AQFP VLSI design flow is capable of converting a high-level described system into physical fabrication. Analysis suggests that a reduction of more than 40% in circuit area and much higher design efficiency can be obtained, comparing to a previous manual design. Index Terms—superconducting integrated circuits, Josephson integrated circuits, HDL, AQFP logic, logic synthesis, EDA tools Fig. 1: Schematic of an AQFP gate. I. INTRODUCTION N the past few years, superconductor-based logic families 1000 Josephson junctions. Test results presented wide margin, I have drawn attention as a means to build next genera- and stable output waveforms [7]. In 2015, a benchmark circuit tion computing systems. Rapid single-flux-quantum (RSFQ) of 10k gate-scale with more than 20,000 Josephson junctions logic [1] is considered to be the most well developed su- has been demonstrated with excitation currents margin of perconductor logic family with high clock speed and low ±20% and very promising yields [8].
    [Show full text]
  • Superconducting Microelectronics for Next-Generation Computing
    Superconducting Microelectronics for Next-Generation Computing Leonard M. Johnson 2018 MIT Research and Development Conference 14 November 2018 DISTRIBUTION STATEMENT A. Approved for public release. © 2018 Massachusetts Institute of Technology. Distribution is unlimited. Delivered to the U.S. Government with Unlimited Rights, as defined in This research was funded by the Office of the Director of National Intelligence DFARS Part 252.227-7013 or 7014 (Feb 2014). Notwithstanding any (ODNI), Intelligence Advanced Research Projects Activity (IARPA) under Air copyright notice, U.S. Government rights in this work are defined by DFARS Force Contract No. FA8721-05-C-0002. The views and conclusions contained 252.227-7013 or DFARS 252.227-7014 as detailed above. Use of this work herein are those of the authors and should not be interpreted as necessarily other than as specifically authorized by the U.S. Government may violate representing the official policies or endorsements, either expressed or implied, any copyrights that exist in this work. of ODNI, IARPA, or the US Government. Computing Development Timeline Triode vacuum Transistor First fully transistor- 30k transistors: 4.5M transistors: 19.2B transistors: ENIAC tube invented invented based computer: TX-0 i8088 Pentium 32-core Epyc GPU 1907 1946 2017 1971 Vacuum tubes Discrete Bipolar transistor CMOS transistors integrated circuits integrated circuits Superconducting Elec - 2 *RSFQ: Rapid Single Flux Quantum L. M. Johnson 11/14/2018 **AQFP: Adiabatic Quantum Flux Parametron Computing Development Timeline Triode vacuum Transistor First fully transistor- 30k transistors: 4.5M transistors: 19.2B transistors: ENIAC tube invented invented based computer: TX-0 i8088 Pentium 32-core Epyc CPU 1907 1946 2017 1971 Vacuum tubes Cryotron IBM Latching Logic RSFQ* Circuits AC-Clocking AQFP** Circuits Superconducting Elec - 3 *RSFQ: Rapid Single Flux Quantum L.
    [Show full text]
  • Superconducting Digital Logic Families Using Quantum Phase-Slip Junctions
    Superconducting Digital Logic Families Using Quantum Phase-slip Junctions by Uday Sravan Goteti A dissertation submitted to the Graduate Faculty of Auburn University in partial fulfillment of the requirements for the Degree of Doctor of Philosophy Auburn, Alabama May 4, 2019 Keywords: Superconducting electronics, quantum phase-slip junctions, Josephson junctions, charge-based logic, single-flux quantum, reversible computing. Copyright 2019 by Uday Sravan Goteti Approved by Michael C. Hamilton, Chair, Associate Professor of Electrical and Computer Engineering Masoud Mahjouri-Samani, Assistant Professor of Electrical and Computer Engineering Mark L. Adams, Assistant Professor of Electrical and Computer Engineering Ryan B. Comes, Assistant Professor of Physics Minseo Park, Professor of Physics Abstract Superconducting electronics based computing is being actively pursued as an alternative to CMOS-based computing for high performance computing due to their inherent advantages such as low-power and high switching speed. These circuits are predominantly based on Josephson junctions. In this work, superconducting digital electronic circuits based on a device called quantum phase-slip junction are explored. Quantum phase-slip junctions are dual to Josephson junctions based on charge-flux duality of Maxwell's equations. Therefore, incorporating these devices into superconducting computers could lead to certain advantages that may overcome some of the challenges currently faced by Josephson junction based circuits, as explained in later chapters in this document. Three different superconducting logic circuit families are introduced using quantum phase-slip junctions and Josephson junctions, namely charge-based logic family, comple- mentary quantum logic family and adiabatic quantum charge parametron logic family, with different advantages and challenges for each of the circuit families.
    [Show full text]
  • Superconductor Digital Electronics: Scalability and Energy Efficiency Issues
    1 Superconductor Digital Electronics: Scalability and Energy Efficiency Issues Sergey K. Tolpygo Abstract—Superconductor digital electronics using Josephson results from a sequential transfer of proton excitation, a proton junctions as ultrafast switches and magnetic-flux encoding of exciton, along a chain of hydrogen bonds between two information was proposed over 30 years ago as a sub-terahertz biopolymers, an actin-myosin pair [6],[7]. A pulling force is clock frequency alternative to semiconductor electronics based produced due to lowering the excited proton energy and on complementary metal-oxide-semiconductor (CMOS) transistors. Recently, interest in developing superconductor shortening the bond length [8]. The initial excitation is electronics has been renewed due to a search for energy saving provided by hydrolysis of an adenosine-triphosphate (ATP) solutions in applications related to high-performance computing. molecule. A high energy efficiency of muscle contraction is The current state of superconductor electronics and fabrication explained in this model as due to energy recycling - the energy processes are reviewed in order to evaluate whether this remaining in a hydrogen bond after a microscopic electronics is scalable to a very large scale integration (VLSI) displacement of the polymers is transferred to a neighboring required to achieve computation complexities comparable to CMOS processors. A fully planarized process at MIT Lincoln bond along the chain, and so on [9]. The original model was Laboratory, perhaps the most advanced process developed so far further developed by Tolpygo and his collaborators in a series for superconductor electronics, is used as an example. The of work; see [10]-[12] and references therein.
    [Show full text]