IBM (NYSE: IBM) announced it has successfully joined and cooled two cryogenic modules into a single environment, marking a milestone in its effort to build a fault-tolerant quantum computer.

The two connected modules stand more than 8 feet tall and 8 feet wide. Testing showed the system can cool to 4 Kelvin in under five days, reaching a final temperature below 15 millikelvin. Each module's vacuum enclosure offers up to 12 times more wiring space than IBM's most widely used quantum systems.

IBM's new box-shaped, modular design allows units to connect in a row and use its "L-coupler" technology to link separate quantum chips so they can share information and operate as part of a larger system. By 2027, IBM's roadmap calls for L-couplers to connect multiple processors into a quantum computer with at least 1,000 programmable qubits. IBM plans to install its Quantum Nighthawk processors into the modules later this year for expanded performance testing.

The architecture is intended to scale toward IBM Quantum Starling, which IBM describes as its target for the world's first fault-tolerant quantum computer, planned for delivery in 2029. At that stage, IBM plans for each cryogenic module to house thousands of qubits.

"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."

The announcement is based on a press release issued by IBM from Yorktown Heights, N.Y.