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

Applied Physics Letters

Demonstration of chip-to-chip transmission of single-flux-quantum pulses at throughputs beyond 100 Gbps

Yoshihito Hashimoto, Shinichi Yorozu, T. Satoh, Toshiyuki Miyazaki

Published Jul 5, 2005• 43 citations
Publisher

Abstract

We report a demonstration of single-flux-quantum (SFQ) pulse transmission between superconductor chips at throughputs beyond 100 Gbps. A fabrication process with a high junction critical current density of 10kA∕cm2 was used to increase the operation speed of a pulse driver and receiver. The chips were flip-chip bonded on a passive microstrip carrier using small solder bumps with diameters of 30μm. With experiments based on a ring-shaped circuit, chip-to-chip SFQ pulse transmission has been demonstrated up to 117 Gbps with an error rate of less than 10−15. The power dissipated by the driver and receiver was only 0.24μW at 117 Gbps.

DOI
10.1063/1.1993767

Related papers

Transmission of single-flux-quantum pulse between superconductor chips

Yoshihito Hashimoto, Shinichi Yorozu, Toshiyuki Miyazaki

Single-flux-quantum (SFQ) pulse transmission between superconductor chips mounted on a passive microstrip carrier is reported. In contrast to the earlier work based on a double-flux-quantum (DFQ) driver, we used an SFQ driver; that is, the simplest driver. To deal with transmission loss at solder-bump bonds, we improved the receiver’s sensitivity by reducing its critical current, and optimized the SFQ driver to have as large an output amplitude as possible with a sufficient bias margin. Chip-to-chip transmission on a passive microstrip carrier with 50μm solder-bump bonds up to 60Gbps has been achieved at a junction critical current density of 2.5KA∕cm2.

Applied Physics Letters•Feb 4, 2005•15 citations

Demonstration of chip-to-chip propagation of single flux quantum pulses

Masaaki Maezawa, Hirotake Yamamori, Alexandre Shoji

We report experimental results on chip-to-chip transfer of single-flux-quantum (SFQ) pulses using an active multichip module (MCM). Josephson transmitters and receivers are integrated on both a chip and an MCM substrate. An MCM consisting of a 4.8-mm chip and an 8.2-mm MCM substrate was fabricated using a 1.6-kA/cm/sup 2/ Nb-trilayer process and a solder-bumped flip-chip bonding technology. The correct operation of the circuit was confirmed by low-speed testing. Bit-error rate (BER) of the circuit was measured down to 10/sup -5/, and extrapolation of the error-function fits suggested a very small BER, lower than 10/sup -200/, at the optimum bias point. Experimental margins on the bias voltage were as large as /spl plusmn/34%.

IEEE Transactions on Applied Superconductivity•Mar 1, 2001•6 citations

High-speed interchip data transmission technology for superconducting multi-chip modules

Deepnarayan Gupta, W. Li, Steven B. Kaplan +1 more

We have developed an interchip data transmission scheme through passive transmission lines on a multi-chip-module (MCM) carrier and 100-/spl mu/m solder bump bonds. In rapid single flux quantum (RSFQ) logic, digital data are in the form of single flux quantum (SFQ) pulses. A reliable scheme for transmission of SFQ pulses through non-superconducting solder bumps between chips through a passive MCM substrate is yet to be established. Therefore, we have devised a scheme that converts SFQ pulses into toggles in a voltage waveform for interchip transmission. Data in the form of SFQ pulses are reconstructed from this voltage waveform using a sensitive quantizing pulse receiver. Our objective is to eliminate the need for amplification of the transmitted signal. This is achieved by increasing the receiver sensitivity. However, a sensitive receiver, a dc SQUID, may produce more than one SFQ pulse for each rising/falling edge of the voltage waveform. A simple circuit, pulse resurrection logic (PRL), is employed to discard any extra SFQ pulses. Together with the sensitive quantizer, the PRL circuit makes our scheme error tolerant. We have demonstrated the receiver operation using 3-/spl mu/m Nb RSFQ circuits at frequencies up to 20 GHz.

IEEE Transactions on Applied Superconductivity•Mar 1, 2001•15 citations

Ballistic SFQ signal propagation on-chip and chip-to-chip

Quentin Herr, M. S. Wire, Andrew D. Smith

We recently reported communication up to 60 Gb/s between digital superconductor chips mounted on a passive carrier, using a novel driver circuit that produces a double-flux-quantum pulse. Here, we answer various practical questions pertaining to chip-to-chip and on-chip communication in greater detail. On-chip, the traditional single-flux-quantum driver is adequate, although margins and bit error rate degrade significantly at the microstrip resonance frequency. Chip-to-chip, using the double-flux-quantum driver, shows little frequency dependence, in spite of 13% reduction of signal current in the chip-to-chip transitions. Appropriate microstrip impedance is in the range 4-8 /spl Omega/ for a 4 kA/cm/sup 2/ Josephson junction IC process. Data includes bit errors rates for pseudo-random data in the range 3-27 Gb/s.

IEEE Transactions on Applied Superconductivity•Jun 1, 2003•28 citations

High speed data link between digital superconductor chips

Quentin Herr, Andrew D. Smith, M. S. Wire

Superconductor digital devices using single-flux-quantum (SFQ) data encoding offer higher speed at lower power than any other integrated circuit technology. For this very reason, interconnect is challenging. We report SFQ data transfer between chips flip chip mounted on a passive microstrip carrier. The flip-chip structure achieves bandwidths greater than 250 GHz. Unlike previous designs, our signal lines are terminated at both ends; this is accomplished using a driver that produces a double-flux-quantum signal. We measured the circuit for pseudorandom data in the range of 10–60 Gb/s. Bit error rates are measured down to 1E−10 and extrapolate to negligible values. The signal power on the microstrip is only 30 nW at 60 Gb ps.

Applied Physics Letters•Apr 29, 2002•58 citations

Design and testing of high-speed interconnects for superconducting multi-chip modules

S Narayana, V K Semenov, Y A Polyakov +2 more

Superconducting single flux quantum (SFQ) circuits can process information at extremely high speeds, in the range of hundreds of GHz. SFQ circuits are based on Josephson junction cells for switching logic and ballistic transmission for transferring SFQ pulses. Multi-chip modules (MCMs) are often used to implement larger complex designs, which cannot be fit onto a single chip. We have optimized the design of wideband interconnects for transferring signals and SFQ pulses between chips in flip-chip MCMs and evaluated the importance of several design parameters such as the geometry of bump pads on chips, length of passive microstrip lines (MSLs) and number of corners in MSLs as well as flux trapping and fabrication effects on the operating margins of the MCMs. Several test circuits have been designed to evaluate the above mentioned features and fabricated in the framework of a 4.5 kA cm −2 HYPRES process. The MCM bumps for electrical connections have been deposited using a wafer-level electroplating process. We have found that, at the optimized configuration, the maximum operating frequency of the MCM test circuit, a ring oscillator with chip-to-chip connections, approaches 100 GHz and is not noticeably affected by the presence of MCM interconnects, decreasing by only about 3% with respect to the same circuit with no inter-chip connections.

arXiv:1206.6120•Superconductor Science and Technology•Aug 30, 2012•31 citations
We report a demonstration of single-flux-quantum (SFQ) pulse transmission between superconductor chips at throughputs beyond 100 Gbps. A fabrication process with a high junction critical current density of 10kA∕cm2 was used to increase the operation speed of a pulse driver and receiver. The chips were flip-chip bonded on a passive microstrip carrier using small solder bumps with diameters of 30μm. With experiments based on a ring-shaped circuit, chip-to-chip SFQ pulse transmission has been demonstrated up to 117 Gbps with an error rate of less than 10−15. The power dissipated by the driver and receiver was only 0.24μW at 117 Gbps.
Single-flux-quantum (SFQ) pulse transmission between superconductor chips mounted on a passive microstrip carrier is reported. In contrast to the earlier work based on a double-flux-quantum (DFQ) driver, we used an SFQ driver; that is, the simplest driver. To deal with transmission loss at solder-bump bonds, we improved the receiver’s sensitivity by reducing its critical current, and optimized the SFQ driver to have as large an output amplitude as possible with a sufficient bias margin. Chip-to-chip transmission on a passive microstrip carrier with 50μm solder-bump bonds up to 60Gbps has been achieved at a junction critical current density of 2.5KA∕cm2.
We report experimental results on chip-to-chip transfer of single-flux-quantum (SFQ) pulses using an active multichip module (MCM). Josephson transmitters and receivers are integrated on both a chip and an MCM substrate. An MCM consisting of a 4.8-mm chip and an 8.2-mm MCM substrate was fabricated using a 1.6-kA/cm/sup 2/ Nb-trilayer process and a solder-bumped flip-chip bonding technology. The correct operation of the circuit was confirmed by low-speed testing. Bit-error rate (BER) of the circuit was measured down to 10/sup -5/, and extrapolation of the error-function fits suggested a very small BER, lower than 10/sup -200/, at the optimum bias point. Experimental margins on the bias voltage were as large as /spl plusmn/34%.
We have developed an interchip data transmission scheme through passive transmission lines on a multi-chip-module (MCM) carrier and 100-/spl mu/m solder bump bonds. In rapid single flux quantum (RSFQ) logic, digital data are in the form of single flux quantum (SFQ) pulses. A reliable scheme for transmission of SFQ pulses through non-superconducting solder bumps between chips through a passive MCM substrate is yet to be established. Therefore, we have devised a scheme that converts SFQ pulses into toggles in a voltage waveform for interchip transmission. Data in the form of SFQ pulses are reconstructed from this voltage waveform using a sensitive quantizing pulse receiver. Our objective is to eliminate the need for amplification of the transmitted signal. This is achieved by increasing the receiver sensitivity. However, a sensitive receiver, a dc SQUID, may produce more than one SFQ pulse for each rising/falling edge of the voltage waveform. A simple circuit, pulse resurrection logic (PRL), is employed to discard any extra SFQ pulses. Together with the sensitive quantizer, the PRL circuit makes our scheme error tolerant. We have demonstrated the receiver operation using 3-/spl mu/m Nb RSFQ circuits at frequencies up to 20 GHz.
We recently reported communication up to 60 Gb/s between digital superconductor chips mounted on a passive carrier, using a novel driver circuit that produces a double-flux-quantum pulse. Here, we answer various practical questions pertaining to chip-to-chip and on-chip communication in greater detail. On-chip, the traditional single-flux-quantum driver is adequate, although margins and bit error rate degrade significantly at the microstrip resonance frequency. Chip-to-chip, using the double-flux-quantum driver, shows little frequency dependence, in spite of 13% reduction of signal current in the chip-to-chip transitions. Appropriate microstrip impedance is in the range 4-8 /spl Omega/ for a 4 kA/cm/sup 2/ Josephson junction IC process. Data includes bit errors rates for pseudo-random data in the range 3-27 Gb/s.
Superconductor digital devices using single-flux-quantum (SFQ) data encoding offer higher speed at lower power than any other integrated circuit technology. For this very reason, interconnect is challenging. We report SFQ data transfer between chips flip chip mounted on a passive microstrip carrier. The flip-chip structure achieves bandwidths greater than 250 GHz. Unlike previous designs, our signal lines are terminated at both ends; this is accomplished using a driver that produces a double-flux-quantum signal. We measured the circuit for pseudorandom data in the range of 10–60 Gb/s. Bit error rates are measured down to 1E−10 and extrapolate to negligible values. The signal power on the microstrip is only 30 nW at 60 Gb ps.
Superconducting single flux quantum (SFQ) circuits can process information at extremely high speeds, in the range of hundreds of GHz. SFQ circuits are based on Josephson junction cells for switching logic and ballistic transmission for transferring SFQ pulses. Multi-chip modules (MCMs) are often used to implement larger complex designs, which cannot be fit onto a single chip. We have optimized the design of wideband interconnects for transferring signals and SFQ pulses between chips in flip-chip MCMs and evaluated the importance of several design parameters such as the geometry of bump pads on chips, length of passive microstrip lines (MSLs) and number of corners in MSLs as well as flux trapping and fabrication effects on the operating margins of the MCMs. Several test circuits have been designed to evaluate the above mentioned features and fabricated in the framework of a 4.5 kA cm −2 HYPRES process. The MCM bumps for electrical connections have been deposited using a wafer-level electroplating process. We have found that, at the optimized configuration, the maximum operating frequency of the MCM test circuit, a ring oscillator with chip-to-chip connections, approaches 100 GHz and is not noticeably affected by the presence of MCM interconnects, decreasing by only about 3% with respect to the same circuit with no inter-chip connections.