IBM connects two quantum fridges in step toward fault-tolerant computing

IBM International Business Machines Corporation ↘ 0.80% announced Wednesday that it has successfully joined and cooled two modular cryogenic systems into a single ultra-cold environment, marking a key engineering step on its path to building a fault-tolerant quantum computer by 2029.stocktitan+1

The connected modules reached a temperature below 15 millikelvin — more than 180 times colder than deep space — with initial tests showing the system can cool to 4 Kelvin in under five days. Combined, the two modules stand more than 8 feet tall and 8 feet wide, and each vacuum enclosure provides up to 12 times more wiring space than IBM's most widely used quantum systems.stocktitan

A Modular Path to Scale

The new box-shaped architecture is designed so modules can connect in a tight row, using IBM's "L-coupler" technology to directly link separate quantum chips. L-couplers allow chips to share information and operate as part of a larger system. By 2027, IBM plans to use L-couplers to reach at least 1,000 programmable qubits, and will install its Quantum Nighthawk processors into the cryogenic modules later this year to begin expanded performance testing.prnewswire

The milestone advances IBM's roadmap toward IBM Quantum Starling, which the company expects to be the world's first fault-tolerant quantum computer when delivered in 2029. At that point, IBM plans for each cryogenic module to house thousands of qubits.stocktitan

Engineering for Fault Tolerance

IBM first introduced its Starling plans last year alongside a new error correction code that reduces the physical resources needed for fault tolerance. Since then, the company says it has demonstrated core hardware components and achieved breakthroughs in efficient error-correction decoding.prnewswire

"Bringing fault-tolerant quantum computers to industries depends on several fundamental advances," said Jay Gambetta, Director of IBM Research and IBM Fellow. "The successful connection and operation of these cryogenic modules signals a leap forward in that direction and will accelerate our progress alongside continued innovation in quantum hardware, software, and algorithms."stocktitan

IBM noted that three essential components of its existing Quantum System Two environment are built into the new architecture, but redesigned so each part can be independently tested, improved, and rapidly iterated — a structure the company expects will speed its pace of innovation.prnewswire