IBM Links 2 Nighthawk Quantum Chips at 99% Fidelity With 4 Meter-Scale Couplers
Updated
Updated · IBM · Oct 27
IBM Links 2 Nighthawk Quantum Chips at 99% Fidelity With 4 Meter-Scale Couplers
3 articles · Updated · IBM · Oct 27
Summary
IBM connected two Quantum Nighthawk R1 processors with four 80-centimeter l-couplers inside a dilution refrigerator, reporting quantum state transfer fidelity of up to 99.3% and 99% on average.
The links are designed to move quantum information reliably between separate superconducting chips, a requirement for modular systems that scale beyond a single processor toward fault-tolerant machines.
IBM also built distant CZ gates across the modules, reaching 94.75% average two-qubit gate fidelity and generating entangled states shared between the two processors.
The company said the inter-chip design is compatible with Nighthawk and intended to scale to its planned Starling architecture, with next steps focused on better yield, lower error rates and more plug-and-play couplers.
IBM linked two quantum chips with 80-centimeter superconducting cables—but can modular connections really beat one bigger chip on the road to fault tolerance?
IBM achieved 99% state transfer between quantum processors, but is 94.75% inter-chip gate fidelity enough for real error-corrected computing?
If future quantum computers look more like modular data centers than giant chips, what engineering problem becomes the true bottleneck next?