SEEQC Reports First Quantum Computer with Integrated Qubit Control on a Chip at Millikelvin Temperatures

SEEQC has published a study in Nature Electronics documenting the operation of a full-stack quantum computing system with integrated digital superconducting logic at 10 mK. The research demonstrates an active quantum processing unit where superconducting digital control circuits are integrated with a five-qubit quantum chip in the same cryogenic environment. Flip-chip bonding creates a multi-chip module allowing digital logic to function alongside qubits. The hardware uses Single Flux Quantum digital pulses to generate control signals locally within the dilution refrigerator. Digital demultiplexing distributes pulses to multiple qubits through shared pathways, breaking the linear scaling of control lines. Power dissipation is measured in nanowatts per qubit. Experimental data from the five-qubit processor indicates single-qubit gate fidelities exceeding 99.5 percent, with peaks reaching 99.9 percent. Benchmarking confirmed the absence of detectable quasiparticle poisoning. The integration provides an alternative to room-temperature electronics SEEQC's roadmap includes integrating digital flux control and digital qubit readout on the die. The objective is a fully integrated quantum system where quantum and classical operations occur in the same cryogenic platform.