IBM unveiled its experimental Loon quantum processor on November 12. Reuters reported that the company had not disclosed when outsiders could test it.
Gartner analyst Mark Horvath told the agency that the approach required additional connections between qubits, making the chips harder to build.
Nighthawk for users
In its announcement, IBM expected Nighthawk deliveries by year-end and specified:
- 120 qubits linked by 218 tunable couplers;
- connections to four nearest neighbours in a square lattice;
- circuits with up to 5,000 two-qubit gates.
Fabrication across two locations
A same-day technical account described production at Albany NanoTech in New York, United States. The process used several wafer types, with additional custom processing at Yorktown. Multiple chips were connected in a three-dimensional stack and linked to control electronics.
Some 300mm wafers were cored to 200mm for further custom steps. Final assembly was followed by testing in dilution refrigerators. The Albany facility processed wafers around the clock, seven days a week.
The August collaboration with AMD
On August 26, IBM and AMD had announced plans to combine quantum systems with high-performance computing. They were exploring integration of AMD central processors, graphics processors and programmable logic chips with IBM machines.
The partners planned an initial demonstration later in 2025 involving hybrid quantum-classical workflows. They also intended to explore how open-source ecosystems, including Qiskit, could support algorithms for this architecture. The announcement envisaged different parts of a problem being handled by the computing approach best suited to them.
November research-plan review
On November 6, DARPA named IBM among eleven companies selected for Stage B of its Quantum Benchmarking Initiative. The yearlong stage covered detailed research and development plans, associated technical risks, mitigation and the prototypes needed to reduce those risks.
IBM's announcement on that date also said it aimed to explore new ways of scaling quantum-computer control systems with SEEQC. This was an exploration planned within the initiative.