Google announced this week that it has developed a new piece of technology that can perform a computation that would take today’s fastest computers 10 septillion years (longer than the age of our universe) in under five minutes.
It’s called “Willow” and it is a quantum chip fabricated at Google’s new, state-of-the-art facility in Santa Barbara, Calif.
Before we go any further, let’s quickly go over what “quantum” means and how it is different from “classical” when it comes to physics and computing.
According to The Quantum Atlas, classical physics refers to the physical laws that govern the behavior of ordinary objects. In the classical realm, things generally stay were you leave them or follow predictable patterns of movement.
“For example, your car keys typically stay right where you put them an hour ago and don’t reappear in the refrigerator,” said The Quantum Atlas.
In the quantum realm, objects don’t have predictable movements. Instead of staying in one place or moving along one path, objects in this realm can act like they are following many different paths.
“While NASA can keep track of the precise path taken by an ordinary spacecraft on its journey, they would have no such luck with a quantum one,” The Quantum Atlas explained. “The best they could do is launch it and then use quantum physics to calculate the probability that the spacecraft reaches a given point at a given time.”
Hartmut Neven, founder and lead of Google Quantum AI, explained in a Monday blog post that errors are a big challenge in quantum computing. That’s because qubits, the units of computation in these computers, “have a tendency to rapidly exchange information with their environment, making it difficult to protect the information needed to complete a computation,” he said. With more qubits, the risk of errors typically increases.
Willow is different. Neven said that this chip actually reduces errors “exponentially as we scale up using more qubits,” an error correction achievement that people in the field have been working on for nearly three decades.
So, Willow has cleared two important benchmarks. The first was the “unfakable” sign of reducing errors with its 105 qubits. The second is the random circuit sampling (RCS) benchmark, the hardest benchmark for quantum computers that measures whether they can do something classical computers can’t do. In Willow’s case, that was performing the computation that would take other computers 10 septillion years. Google’s assessment indicates it outperformed one of the most powerful classical computers, Frontier.
“This mind-boggling number exceeds known timescales in physics and vastly exceeds the age of the universe,” said Neven. “It lends credence to the notion that quantum computation occurs in many parallel universes, in line with the idea that we live in a multiverse, a prediction first made by David Deutsch.”
Neven founded Google Quantum AI in 2012, a journey that would lead to the creation of Willow.
“The vision was to build a useful, large-scale quantum computer that could harness quantum mechanics — the “operating system” of nature to the extent we know it today — to benefit society by advancing scientific discovery, developing helpful applications, and tackling some of society’s greatest challenges,” he said.
While Willow is a significant step forward, there’s more work to be done. Specifically Neven noted that the next challenge is to demonstrate a first useful computation on quantum chips that is relevant to a real-world application.
“We’ve done scientifically interesting simulations of quantum systems, which have led to new scientific discoveries but are still within the reach of classical computers,” Neven said, adding that his team’s goal is to “step into the realm of algorithms that are beyond the reach of classical computers and that are useful for real-world, commercially relevant problems.”
He said that Google Quantum AI is inviting researchers, engineers and developers to join the effort by checking out its open source software and educational resources, including a new course on Coursera. As research continues, Willow now stands as “the most convincing prototype for a scalable logical qubit built to date,” Neven said.
Going forward, he said “quantum computation will be indispensable for collecting training data that’s inaccessible to classical machines, training and optimizing certain learning architectures, and modeling systems where quantum effects are important.” Those capabilities could then help with the discovery of new medicines, designing more efficient batteries for electric cars, and accelerating progress in fusion and new energy alternatives.
“Many of these future game-changing applications won’t be feasible on classical computers; they’re waiting to be unlocked with quantum computing,” that Willow paves the way to, Neven added.