Many MindedIBM revises quantum plan: two linked chips, 1,040 qubits, due 2027
At its Quantum Developer Conference this week, IBM updated its quantum roadmap. The company plans to offer a 1,040-qubit system in 2027 by linking two Nighthawk chips. That replaces the earlier plan to link nine 120-qubit chips for 1,080 qubits. The Nighthawk r3 chip, also planned for 2027, targets 520 programmable qubits, so total qubit count for next year stays about the same. IBM's stated goal remains error-corrected quantum computers before the end of the decade.
The previous roadmap called for linking three Nighthawk processors in 2026 for a 360-qubit machine. Nighthawk r2, released in September 2026, is a single chip with 458 physical qubits, 120 of them programmable. The extra qubits handle hardware-based resets, which IBM says speed up some operations by up to 19 times. IBM's Oliver Dial said four L-couplers joining two Nighthawk r1 processors in one refrigerator reached state transfer fidelity of up to 99.4 percent, against a long-term target of 99.9 percent. CTO Jerry Chow said chip-to-chip connection speed is comparable to on-chip interconnects. IBM has also demonstrated a modular dilution refrigerator that can cool multiple chips and connectors.
Why it matters: fault-tolerant machines are what would make quantum computing useful for science and materials research, with possible knock-on benefits for health. IBM's long-term plan uses about 300 hardware qubits per block of 12 logical qubits. Reaching 100 or more logical qubits would need larger chips and five or more linked chips, so reliable linking is the central engineering task.
Caveats: the 99.4 percent figure was measured on r1 chips, not the planned r3 hardware. Dial acknowledged IBM is still working out how many couplers are needed to link chips hosting error-corrected qubits. Practical usefulness of these systems remains unproven.
Source: Ars Technica