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

Proceedings of the IEICE General Conference

SC-8-6 FABRICATION AND OPERATION OF SFQ-DC CONVERTER FOR USE IN OXIDE SFQ CIRCUIT

Y. Tarutani, Yoshihiro Ishimaru, Hironori Wakana, Ken‐ichi Nakayama, S. Adachi, Yasuo Oshikubo, Osami Horibe, Yusuke Omori, Kousuke Tanabe

Published Mar 8, 2004• 0 citations
OpenAlex

Related papers

New type of SFQ-dc converter for use in oxide circuits

Y. Tarutani, Yoshihiro Ishimaru, H. Wakana +6 more

Physica C Superconductivity•Jun 3, 2004•13 citations

Pulse Response of Mutually-Coupled dc-to-SFQ Converter Investigated using an On-Chip Pulse Generator

Tomoki Watanabe, Yoshiaki Urai, Hiroshi Shimada +1 more

A readout technique using single-flux-quantum (SFQ) circuits enables superconducting single photon detectors (SSPDs) to operate at further high-speed, where a mutually-coupled dc-to-SFQ (MC-dc/SFQ) converter is used as an interface between SSPDs and SFQ circuits. In this work, we investigated pulse response of the MC-dc/SFQ converter. We employed on-chip pulse generators to evaluate pulse response of the MC-dc/SFQ converter for various pulses. The MC-dc/SFQ converter correctly operated for the pulse current with the amplitude of 52 μA and the width of 179 ps. In addition, we examined influence of the pulse amplitude and width to operation of the MC-dc/SFQ converter by numerical simulation. The simulation results indicated that the MC-dc/SFQ converter had wide operation margins for pulse current with amplitudes of 30–60 μA irrespective of the pulse widths.

IEICE Transactions on Electronics•Jan 1, 2015•0 citations

Fabrication and characteristics of SFQ circuit elements made of oxide thin films

Y. Tarutani, Yoshihiro Ishimaru, H. Wakana +7 more

Physica C Superconductivity•Aug 9, 2005•2 citations

Study of Signal Interface between Single Flux Quantum Circuit and Adiabatic Quantum Flux Parametron

Fumihiro China, Tatsuya Narama, Naoki Takeuchi +3 more

We investigated interface circuits between a single-flux-quantum (SFQ) circuit and an adiabatic quantum-flux-parametron (AQFP) for their hybrid system. The target frequency of interface circuits is several GHz. The interface circuit that transmits a signal from the SFQ circuit to the AQFP gate (SFQ/AQFP) is realized by combining an SFQ toggle flip-flop (TFF) with the AQFP buffer. The bias margin of the SFQ TFF and the excitation current margin of the SFQ/AQFP interface are 2.47 mV ±24.7% and 1.36 mA ±8.82%, respectively. The interface circuit that transmits a signal from the AQFP to the SFQ circuit (AQFP/SFQ) was designed by using a high-sensitive mutually coupled dc/SFQ converter (MC-dc/SFQ) to detect magnetic flux signal output from the AQFP. The bias margin of the high-sensitive MC-dc/SFQ and the excitation current margin of the AQFP/SFQ are 2.88 mV ±13% and 1.6 mA ±18.8%, respectively. These interface circuits also allow us to use long-distance interconnection based on SFQ passive transmission lines between AQFP gates.

IEEE International Superconductive Electronics Conference (ISEC)•Jul 1, 2015•0 citations

Fabrication and Logic Operation of Oxide SFQ-Circuit-Components

Y. Tarutani, Yoshihiro Ishimaru, H. Wakana +6 more

Basic SFQ circuit components, such as SFQ-dc converter, set-reset flip-flop (RS-FF), confluence buffer and splitter, have been fabricated by the YBa/sub 2/Cu/sub 3/O/sub 7-x/-ramp-edge-junction technology and their logic operations were investigated. Circuit parameters were optimized in order to widen the margins of these oxide SFQ circuit components. The SFQ-dc converter that comprised double SQUIDs connected in series showed the output voltage as much as 0.3 mV at 22 K owing to high I/sub c/R/sub n/ value of the ramp-edge junction. Logic operations of the RS-FF, the confluence buffer and the splitter were correctly performed by using the SFQ-dc converter. Finite operating margins were obtainable for these circuits up to the temperature near 30 K.

IEEE Transactions on Applied Superconductivity•Jun 1, 2005•21 citations

Influence of parasitic capacitance on the oxide SFQ circuit operation

Y. Tarutani, Koji Tsubone, H. Wakana +5 more

Physica C Superconductivity•Jun 4, 2007•3 citations
A readout technique using single-flux-quantum (SFQ) circuits enables superconducting single photon detectors (SSPDs) to operate at further high-speed, where a mutually-coupled dc-to-SFQ (MC-dc/SFQ) converter is used as an interface between SSPDs and SFQ circuits. In this work, we investigated pulse response of the MC-dc/SFQ converter. We employed on-chip pulse generators to evaluate pulse response of the MC-dc/SFQ converter for various pulses. The MC-dc/SFQ converter correctly operated for the pulse current with the amplitude of 52 μA and the width of 179 ps. In addition, we examined influence of the pulse amplitude and width to operation of the MC-dc/SFQ converter by numerical simulation. The simulation results indicated that the MC-dc/SFQ converter had wide operation margins for pulse current with amplitudes of 30–60 μA irrespective of the pulse widths.
We investigated interface circuits between a single-flux-quantum (SFQ) circuit and an adiabatic quantum-flux-parametron (AQFP) for their hybrid system. The target frequency of interface circuits is several GHz. The interface circuit that transmits a signal from the SFQ circuit to the AQFP gate (SFQ/AQFP) is realized by combining an SFQ toggle flip-flop (TFF) with the AQFP buffer. The bias margin of the SFQ TFF and the excitation current margin of the SFQ/AQFP interface are 2.47 mV ±24.7% and 1.36 mA ±8.82%, respectively. The interface circuit that transmits a signal from the AQFP to the SFQ circuit (AQFP/SFQ) was designed by using a high-sensitive mutually coupled dc/SFQ converter (MC-dc/SFQ) to detect magnetic flux signal output from the AQFP. The bias margin of the high-sensitive MC-dc/SFQ and the excitation current margin of the AQFP/SFQ are 2.88 mV ±13% and 1.6 mA ±18.8%, respectively. These interface circuits also allow us to use long-distance interconnection based on SFQ passive transmission lines between AQFP gates.
Basic SFQ circuit components, such as SFQ-dc converter, set-reset flip-flop (RS-FF), confluence buffer and splitter, have been fabricated by the YBa/sub 2/Cu/sub 3/O/sub 7-x/-ramp-edge-junction technology and their logic operations were investigated. Circuit parameters were optimized in order to widen the margins of these oxide SFQ circuit components. The SFQ-dc converter that comprised double SQUIDs connected in series showed the output voltage as much as 0.3 mV at 22 K owing to high I/sub c/R/sub n/ value of the ramp-edge junction. Logic operations of the RS-FF, the confluence buffer and the splitter were correctly performed by using the SFQ-dc converter. Finite operating margins were obtainable for these circuits up to the temperature near 30 K.