IBM Links Two Cryogenic Modules Below 15 Millikelvin on the Path to Its 2029 Fault-Tolerant Quantum Computer

IBM has successfully integrated and cooled two cryogenic modules within a single shared environment, a step the company calls critical to scaling quantum systems that can eventually link hundreds of quantum chips. The achievement supports IBM’s stated timeline for delivering IBM Quantum Starling in 2029, a system the company expects to be the first fault-tolerant quantum computer, incorporating advances in error correction, processor design, decoding, and overall systems engineering.

The interior of IBM’s scalable and modular cryogenic system to support fault-tolerant quantum computing. (Credit: IBM)

The combined two-module setup measures more than 8 feet tall and 8 feet wide. During initial testing, the modules cooled together to 4 Kelvin, the temperature of liquid helium, in under five days, then reached below 15 millikelvin shortly afterward, more than 180 times colder than deep space. Each module’s vacuum enclosure provides up to 12 times more wiring space than the most widely used IBM quantum systems, a design change intended to support a higher density of chip-to-chip connections both within individual modules and across linked modules.

The modules use a box-shaped design that allows multiple units to connect in a tight row. This layout, combined with the added internal wiring space, enables direct linking of quantum processors through IBM’s L-coupler technology. L-couplers connect separate quantum chips, enabling them to exchange information and function together as components of a larger quantum computer.