Why you should care
Because a quantum computer could change the way we understand reality.
Few people can say they’ve brought about a quantum leap in their field. But if all goes well for Chad Rigetti, this summer he will join them, by making the machine on your desk as obsolete as an abacus.
“We’re on a mission to build the world’s most powerful computer,” says Rigetti, “to solve humanity’s most pressing problems.” Cancer, climate change, world hunger — all targets of the technology Rigetti has in mind. It’s a striking vision for a 38-year-old farm boy from Moose Jaw, Saskatchewan, who once thought he would grow barley after high school.
To achieve his goal — creating the first commercial quantum computer — would amount to a revolution in computing. Conventional computers reduce logic problems to math problems, and math problems to a binary counting system: On or off equals one or zero. The time required to solve difficult problems has been getting shorter and shorter as computer engineers figure out how to make their on/off switches smaller, each year doubling the computing power contained within the same-size box. They now envision the day when they’re working on switches the size of atoms.
But that’s also the point at which they’ll hit a barrier, because subatomic particles behave according to the bizarre rules of quantum mechanics. A single particle can be in two places at once. It can instantly affect another particle light-years away. And it can travel through insulation, so it’s hard to find when you need it.
After more or less blundering into a physics class, Rigetti found himself lured by the mystery of quantum mechanics.
Such unpredictable behavior makes particles such as photons and electrons difficult to control — but it also gives them a kind of superpower. Instead of bits, a quantum computer uses qubits, which can be both on and off at the same time. A conventional processor does one calculation at a time. A quantum processor with one qubit can do two calculations at once. A two-qubit processor can do four, and so on. A 70-qubit processor would be more powerful than the most powerful supercomputer ever built, and a 100-qubit processor would be more powerful than a conventional computer the size of the universe.
Why does this matter? On a grand scale, quantum computers could make quantum mechanics more intuitive, perhaps triggering a shift in human understanding similar to the discovery that the Earth orbits the sun. More practically, they could solve complex problems involving the interactions of multiple variables, enabling them, say, to dramatically accelerate the pattern recognition essential to artificial intelligence. They could also model how molecules interact to create new drugs — or they might develop a fertilizer that sucks greenhouse gases from the atmosphere.
That last example comes readily to Rigetti, who operated a tractor as a teenager. But if you’d asked his high school teachers whether they thought him likely to innovate in the field of agriculture, let alone climate change, the response might have been a collective no. “He probably stood out as being a bit argumentative,” says his mother. “I credit that to the fact that he was curious, and he was challenging the teachers.”
That very combination of combativeness and curiosity propelled Rigetti to where he is today. Rather than academics, Rigetti threw himself into sports, attracting the attention of the wrestling coach at the University of Regina. Once there, however, a torn ligament halted his athletic career — and curiosity took over.
After more or less blundering into a physics class, Rigetti found himself lured by the mystery of quantum mechanics — and he brought a wrestler’s tenacity to the thorniest equations. Eventually his efforts led him to Yale, where he teamed with Michel Devoret, an applied physicist with ideas for grappling with subatomic particles. Devoret proposed refrigerating silicon chips to colder than outer space, a temperature at which they become superconducting. Materials that are superconducting still behave in quantum ways, but their larger size makes it possible to manipulate them far more easily than individual photons and electrons.
Rigetti saw ways to build this idea into an actual quantum computer. From Yale, he took it to IBM, before founding his startup in 2013. Sitting for an interview in a conference room at Rigetti Computing in Berkeley, California, Rigetti sports the requisite Silicon Valley–casual attire: down vest over a pin-striped shirt, and blue sneakers. The newly minted entrepreneur is also newly married, to Susan Fowler, the former Uber engineer whose blog post about sexual harassment at the company was a key factor in forcing its CEO, Travis Kalanick, to take a leave of absence. But while Rigetti may appear nonchalant, he’s anything but laid-back. He is obsessively punctual, runs a meticulously clean laboratory and tightly limits what’s disclosed about the company’s technology.
“Secretive” is the word that Daniel Lidar, a quantum computing expert at the University of Southern California, chooses to describe Rigetti. He has revealed few specifics about the innovations that distinguish his company’s product from those of his competitors, Lidar points out. And the competition is formidable. IBM, Google, Microsoft and Chinese tech giant Alibaba are all racing to invent the first general purpose commercial quantum computer.
What makes Rigetti think he can slay these Goliaths? “It’s like GM versus Tesla,” Rigetti says. “You can do amazing things by building an organization from scratch.” That narrative has so far convinced venture capitalists to lay out $69.2 million, enabling the company to open offices in Berkeley and Fremont, California, and hire physicists from top universities and leading tech companies.
“I know people who work there,” says Seth Lloyd, professor of mechanical engineering at MIT, who devised part of the theoretical framework for quantum computing. “I don’t know if they’re going to win this race, but they are certainly real competitors in it.”
When Rigetti Computing launches its computer — the company promises an announcement this summer — experts such as Lloyd and Lidar have math problems ready to challenge it. If the quantum computer solves them faster than a conventional computer, a new era may be at hand for all of humanity. If not, the world still needs barley.