Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physica C Superconductivity

Single-flux-quantum logic circuits exploiting collision-based fusion gates

Tetsuya Asai, Kazuhito Yamada, Yoshiyuki Amemiya

Published Jun 14, 2008• 4 citations
Publisher
DOI
10.1016/j.physc.2008.05.273

Related papers

Dynamically Reconfigurable Single Flux Quantum Logic Gates

Yuki Yamanashi, 一朗 大河, Yoshikawa Nobuyuki

IEICE Technical Report; IEICE Tech. Rep.•Oct 13, 2009•0 citations

Combinational Logic Computing for Single-Flux Quantum Circuits with Asynchronous Collision-Based Fusion Gates

Kazuhito Yamada, Tetsuya Asai, Yoshihito Amemiya

We propose a single-flux-quantum (SFQ) logic system based on the reactiondiffusion-collision fusion computation. The fusion computation is a way of digital processing that performs logic operation by applying analogy of nonlinear physical and chemical systems to the structure of the logic operation. It is very powerful for implementing a given digital operation with a small number of logic gates. A fusion computation system consists of regularly arrayed unit cells, where each cell has two input arms and two output arms and is connected to its neighboring cells with the arms. Each cell accepts two input signals A and B and produces two output signals AB and AB. A fusion computation system, as a whole, can operate any combinational logic function. We designed functional SFQ circuits that implemented the fusion computation. The unit cell was able to be made with ten Josephson junctions. Circuit simulation showed that SFQ fusion computation systems could operate at very high speed, about ten times faster than conventional CMOS logic systems.

International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)•Jul 1, 2008•3 citations

A single flux quantum logic gate with high functionality

W. Hioe, M. Hosoya, Reiji Suda +1 more

The D-gate is a quantum flux parametron (QFP) logic gate which was proposed to reduce input interaction and improve input margin. It is basically a 2-input multiplexer with two select signals. By giving appropriate inputs, a single gate can also perform 2-input AND, 2-input OR, 2-input XOR, 3-input majority, 3-input parity or 1-bit equality. Since it is a QFP device, it has a self-latching effect which can be exploited for pipelined designs of many combinational logic functions. However, because QFP logic is a clocked logic expected to operate at 10 GHz or more, propagation delay becomes an important issue in circuit design.

Superconductor Science and Technology•Nov 1, 1991•0 citations

New Single-Flux-Quantum Logic Circuits with SQUIDs

Y. Harada

IEICE Transactions on Electronics•Mar 1, 2002•0 citations

Design Approach of Dynamically Reconfigurable Single Flux Quantum Logic Gates

Yuki Yamanashi, 一朗 大河, Nobuyuki Yoshikawa

Novel reconfigurable superconductive single flux quantum (SFQ) logic devices, the functions of which can be dynamically reconfigured by inputting control signals, have been investigated. The characteristics of single flux quantum circuits can be easily modulated by applying currents or magnetic fields because of the high sensitivity of superconductive circuits. We investigated several design approaches for the realization of dynamically reconfigurable SFQ logic devices. We employed direct current injection to the logic gate using a non-destructive read-out flip-flop. By changing the internal state of the non-destructive read-out flip-flop, the logic function can be dynamically reconfigured. We have designed and tested a dynamically reconfigurable Josephson transmission line (JTL)/delay flip-flop (DFF) circuit. The measured dc bias margin was 72.5-107.2%. Furthermore, we have demonstrated the operation of a variable bit-length shift register, composed of the dynamically reconfigurable JTL/DFF circuits. The investigated design approach can be applied to more sophisticated dynamically reconfigurable single flux quantum logic gates.

IEEE Transactions on Applied Superconductivity•Dec 14, 2010•11 citations

Single-Flux-Quantum Logic Devices Based on the Binary Decision Diagram

Noboru Asahi, Takashi Yamada, Masamichi Akazawa +1 more

Springer eBooks•Jan 1, 1999•0 citations
We propose a single-flux-quantum (SFQ) logic system based on the reactiondiffusion-collision fusion computation. The fusion computation is a way of digital processing that performs logic operation by applying analogy of nonlinear physical and chemical systems to the structure of the logic operation. It is very powerful for implementing a given digital operation with a small number of logic gates. A fusion computation system consists of regularly arrayed unit cells, where each cell has two input arms and two output arms and is connected to its neighboring cells with the arms. Each cell accepts two input signals A and B and produces two output signals AB and AB. A fusion computation system, as a whole, can operate any combinational logic function. We designed functional SFQ circuits that implemented the fusion computation. The unit cell was able to be made with ten Josephson junctions. Circuit simulation showed that SFQ fusion computation systems could operate at very high speed, about ten times faster than conventional CMOS logic systems.
The D-gate is a quantum flux parametron (QFP) logic gate which was proposed to reduce input interaction and improve input margin. It is basically a 2-input multiplexer with two select signals. By giving appropriate inputs, a single gate can also perform 2-input AND, 2-input OR, 2-input XOR, 3-input majority, 3-input parity or 1-bit equality. Since it is a QFP device, it has a self-latching effect which can be exploited for pipelined designs of many combinational logic functions. However, because QFP logic is a clocked logic expected to operate at 10 GHz or more, propagation delay becomes an important issue in circuit design.
Novel reconfigurable superconductive single flux quantum (SFQ) logic devices, the functions of which can be dynamically reconfigured by inputting control signals, have been investigated. The characteristics of single flux quantum circuits can be easily modulated by applying currents or magnetic fields because of the high sensitivity of superconductive circuits. We investigated several design approaches for the realization of dynamically reconfigurable SFQ logic devices. We employed direct current injection to the logic gate using a non-destructive read-out flip-flop. By changing the internal state of the non-destructive read-out flip-flop, the logic function can be dynamically reconfigured. We have designed and tested a dynamically reconfigurable Josephson transmission line (JTL)/delay flip-flop (DFF) circuit. The measured dc bias margin was 72.5-107.2%. Furthermore, we have demonstrated the operation of a variable bit-length shift register, composed of the dynamically reconfigurable JTL/DFF circuits. The investigated design approach can be applied to more sophisticated dynamically reconfigurable single flux quantum logic gates.