Scientists Just Built a Fridge 180 Times Colder than Deep Space—It Could Unlock the Quantum Era

3 min readHere’s what you’ll learn when you read this story:• Quantum computers require extremely cold temperatures to maintain coherence, but creating a refrigerator big enough to scale with all the hardware and wiring isn’t easy.• IBM announced earlier this month the creation of a modular system that relies on dilution refrigeration to chill things down to just 15 millikelvins.• This ability to scale cooling architecture with computing power will hopefully help IBM reach its goal of creating a fault-tolerant quantum computer by 2029.Quantum computing is a delicate technology that requires pinpoint energy accuracy, and that means heat, too. Heat causes atoms and electrons to randomly vibrate, and that thermal energy can cause qubits—the building blocks of quantum computing—to decohere and lose their beneficial quantum properties.To avoid such temperature-induced mishaps, quantum tech companies need innovative ways to make things really, really cold. Since late 2018, IBM has been investigating ways to improve and scale up dilution refrigerators, a kind of cryogenic device that cools things down to just a dozen millikelvins or so, which is roughly –459.65 degrees Fahrenheit. To solve this problem, the company began “project Goldeneye” back in 2018 with the goal of creating a dilution refrigerator capable of housing a one-million-qubit quantum processor.“While working on it, it also really made us start thinking beyond, and almost instantly that we will need much larger cryogenic support system to ever cool down between 1,000 to 1 million qubits,” Jerry Chow, director of quantum hardware systems at IBM, told ZDNET in 2022. “It became very apparent that a new way of thinking in terms of the design would be needed and we started coming up with different form factors for how to effectively construct and cool down a behemoth such as the super-fridge.”Back in 2022, IBM announced that it had successfully created its first proof-of-concept design, but earlier this month, the company revealed the next step of its super-cooled vision: a modular system capable of dropping to temps 180 times colder than those in deep space. With two modules combined, the refrigerator is roughly eight feet tall and wide, and can reach four kelvins after just five days of cooling. Using what IBM calls an “L-coupler,” which connects separate quantum chips together, the company can essentially line up as many of these modular refrigerators in a row as needed, with the goal of creating a 1,000-qubit quantum computer by next year.So how exactly do these fridges get so cold? Dilution refrigerators rely on a number of steps to dramatically drop the thermostat. They leverage two helium isotopes, helium-3 and helium-4, and then use vacuum pumps to circulate and dilute those isotopes with the help of a cryo-cooler, a mechanical device that doesn’t rely on baths of liquid cryogens (liquid nitrogen or liquid helium) and is therefore a “dry” method of cooling. This device is what helps cool the helium mixture first to 50 kelvins and eventually down to four kelvins.“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,” IBM’s Jay Gambetta, director of IBM Research, said in a press statement.The hope is that by 2029, the company will be capable of performing 100 million quantum operations per session with the debut of its Starling quantum computer. So far, IBM has only tested connections between two modules, but with this new quantum refrigerator in hand—along with recent breakthroughs in error correction—the future of fault-tolerant quantum computing is looking brighter.“We’ve nailed down the science for fault-tolerant quantum computing, and instead a big part of what we’re doing to get there now is engineering,” Chow said during a press event earlier this month. “It really provides enough space for all the high-density wiring that’s needed. We’re really starting to architect the entire system around one unified powerful system.”Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.