APPLICATIONS OF TECHNOLOGY:
Rapid Single-Flux Quantum (RSFQ) circuits for superconducting digital computing in applications such as:
- High-speed and low power digital circuits
- Quantum computing
- HPC accelerators
- Methodology can design a toggle flip-flop with any number of outputs
- Reduction in area, power, and latency of certain RSFQ compute and memory circuits
Superconducting digital computing predominantly uses single-flux quanta, typically based on the Rapid Single-Flux Quantum (RSFQ) logic family, to encode information and has demonstrated significant improvements in performance compared to Complementary Metal-Oxide-Semiconductor (CMOS). An important building block of popular RSFQ circuits such as registers, counters, frequency dividers, and counting networks, is a toggle flip-flop (TFF). Traditional TFFs have a single input that accepts pulses and distributes them in a round robin manner among its one or two outputs. Because TFFs have only two outputs, larger-scale circuits need multiple TFFs as well as other cells, which drastically increases area.
Scientists at Berkeley Lab have developed a multi-output TFF design which reduces the area, power, and latency of multiple types of compute and memory circuits with multiple outputs. This TFF is a new cell that replaces circuits with tens of cells, leading to a TFF that can have more than two outputs, which can be determined at design time. In TFFs, information is internally temporarily stored in a SQUID loop in the form of magnetic flux quanta. The design methodology of the TFFs includes a process on duplicating the number of SQUIDs and outputs, as well as how to tune every Josephson Junction (the fundamental building block in the circuit) for correct operation.
Characteristic proof of concept.
Meriam Gay Bautista
Available for licensing or collaborative research