IBM builds a better fridge for its quantum computers IBM on Wednesday announced that it has built and cooled the first two modules of a new cryogenic dillution refrigerator designed to house the processors in its future fault-tolerant quantum computers. One major caveat: those refrigerator modules don’t actually house any quantum processors yet, but IBM says plans to install one Nighthawk processor in each unit later this year. This will be the first test of whether processors will work inside the new refrigerator and can communicate across the connection between its modules. That’s a crucial next step for IBM’s quantum ambitions, given that its plans for future quantum computing systems hinge on its ability to efficiently connect multiple individual processors and cryogenic modules into a single system. Why build a better fridge? To work, superconducting quantum processors need to operate at a fraction of a degree above absolute zero to reduce noise, which is, after all, one of the main enemies of stable, long-running quantum computers. At this point in the development of quantum computers, it’s all about building larger, more fault-tolerant machines, but building larger systems isn’t just about adding more qubits. Each processor needs control and readout wiring, shielding, cooling, and electronics. All of that has to fit inside or around the refrigerator without producing too much heat to disrupt the qubits. “It’s really about all the infrastructure and the supporting pieces around it as well in the system,” Jerry Chow, IBM fellow and chief technology officer for quantum-centric supercomputing, pointed out in a press briefing ahead of the announcement. IBM’s new design splits that refrigeration infrastructure into rectangular cells that can be connected to create a shared ultra-cold environment for the quantum processors. The first two modules together measure about 8 feet tall and 8 feet wide