SEEQC and IBM have announced a technical collaboration under DARPA’s Quantum Benchmarking Initiative (QBI) to investigate the integration of SEEQC’s Single Flux Quantum (SFQ) chip-based control technology with IBM’s quantum computing systems. The partnership aims to explore architectural solutions for consolidating classical control elements into cryogenic system-on-a-chip designs operating near quantum processors, enhancing energy efficiency and system compactness.
The collaboration will focus on addressing systems-level engineering challenges that are critical for scaling large fault-tolerant quantum computers. SEEQC’s SFQ-based digital control approach could potentially reduce the need for bulky room-temperature racks by relocating key control components inside dilution refrigerators, next to qubit chips. IBM, which continues to pursue its roadmap toward a fault-tolerant quantum computer by 2029, sees this effort as complementary to its broader goals.
Why This is Important
There are many challenges associated with scaling a superconducting quantum processor. One challenge involves the physical limits of routing the electrical signal wires from the control electronics operating at room temperature to the qubit chips operating at millikelvin temperatures inside the dilution refrigerator. The second challenge involves the limiting cooling capacity of the dilution refrigerator. Several companies are pursuing cryoCMOS solutions to help solve the wiring problem. This solution calls for development of a CMOS chip that can run at a temperature of a few kelvin or lower allowing it to be placed next to or near the qubit chip. So rather than routing through the dilution refrigerator a few control lines for each qubit, a much more limited number of lines are routed to the cryoCMOS chip which contains a small amount of logic and then redistributes the appropriate signals to the individual qubits. (As an example, see our article published last year that describes Intel’s Horse Ridge II and Pando Tree cryoCMOS control chips.)
But cryoCMOS does not fully solve the cooling problem. Although the cryoCMOS may be lower in power, it still consumes power which is dissipated as heat that must be cooled in the dilution refrigerator. This is where SFQ logic comes in. SFQ logic is based upon a concept completely different from CMOS transistors. It uses picosecond-duration voltage pulses using Josephson junctions that encode encode, process, and transport digital information. Not only is SFQ logic much faster than CMOS, but its power dissipation is orders of magnitude less. This helps because dilution refrigerators have limits to their cooling capacity which allows IBM to cram more qubits into an individual dilution refrigerator and build larger systems. (For a more detailed discussion on dilution refrigerator cooling limits, view a section covering this in GQI’s report on The Road to Shor Era Quantum Computing.)
Being Neighbors Helps
Both companies are headquartered in New York and are active participants in the state’s growing quantum ecosystem. Both are located in Westchester County, New York with SEEQC’s headquarters in Elmsford about 7 miles from the IBM Research lab in Yorktown Heights. The collaboration underscores DARPA’s intent to drive performance metrics and benchmarking standards for useful, scalable quantum systems through public-private partnerships. It also highlights the role of regional clusters—such as New York’s NY QUANTUM Consortium—in facilitating progress across the full commercialization continuum.
Read SEEQC’s announcement here.
June 11, 2025
