IBM took a step toward its most powerful quantum computer to date on Wednesday, announcing it had cleared the way for interconnected processors to power much larger systems.
International Business Machines successfully integrated and cooled the first two modules of its new cryogenic architecture, laying the groundwork for scaling the ultra-cold environment needed to link hundreds of quantum chips. The milestone advances IBM's goal to launch Starling, a fault-tolerant quantum supercomputer, before the end of the decade.
Fault tolerance describes a system's ability to keep functioning even when its individual components fail or experience disruptions. While classical machines handle this naturally, quantum systems-which depend on delicate subatomic states-easily succumb to errors.
Achieving fault tolerance at a larger scale remains one of the final barriers to building quantum systems that can perform reliable, advanced calculations.
"When we talk about Starling, we're talking about a machine that's at the scale of 200 cubits and 100 billion operations," Jerry Chow, IBM's head of quantum-centric supercomputing, told Barron's. "People are certainly looking at from a chemistry perspective-that's where there are more of these provable, algorithmic advantages."
Qubits, a portmanteau for quantum bits, are the basic units of information inside a quantum computer. In IBM's case, these are tiny, artificial atoms called superconducting transmon qubits that have been patterned onto a silicon chip, and must be cooled to temperatures colder than deep space in order to work properly.
The fault-tolerant quantum computers of the future will depend on many quantum chips working in tandem on the same problems. To do so, they must be housed in shared spaces that are cooled to very low temperatures.
The architecture unveiled Wednesday allows information to move between chips to enable more sophisticated algorithms. The towering modules, standing more than 8 feet tall and 8 feet wide, are already live at a facility in upstate New York. Initial tests show they can cool down to 4 Kelvin, the temperature of liquid helium, in under 5 days and reach a final temperature below 15 millikelvin shortly after.
Chow, who first joined IBM as a researcher in 2010, envisions Starling as a bridge between IBM's existing quantum systems and Blue Jay, an even more ambitious machine slated for release early next decade.
"We're going to make further advantages when we get to Blue Jay," Chow explained. "It's why we have such exciting engagement with our partners and our clients to explore the types of chemistry problems and things we can really leverage these machines for."
The breakthrough comes just weeks after IBM and research partners released three technical papers showing how quantum calculations can be checked for accuracy in real time, addressing another hurdle on the path to fault-tolerant supercomputers.