Much of the ongoing quantum computing battle among tech giants such as Google and IBM has focused on developing the hardware necessary to solve impossible classical computing problems. A Berkeley-based startup looks to beat those larger rivals with a one-two combo: a fab lab designed for speedy creation of better quantum circuits and a quantum computing cloud service that provides early hands-on experience with writing and testing software.
Rigetti Computing recently unveiled its Fab-1 facility, which will enable its engineers to rapidly build new generations of quantum computing hardware based on quantum bits, or qubits. The facility can spit out entirely new designs for 3D-integrated quantum circuits within about two weeks—much faster than the months usually required for academic research teams to design and build new quantum computing chips. It’s not so much a quantum computing chip factory as it is a rapid prototyping facility for experimental designs.
“We’re fairly confident it’s the only dedicated quantum computing fab in the world,” says Andrew Bestwick, director of engineering at Rigetti Computing. “By the standards of industry, it’s still quite small and the volume is low, but it’s designed for extremely high-quality manufacturing of these quantum circuits that emphasizes speed and flexibility.”
But Rigetti is not betting on faster hardware innovation alone. It has also announced its Forest 1.0 service that enables developers to begin writing quantum software applications and simulating them on a 30-qubit quantum virtual machine. Forest 1.0 is based on Quil—a custom instruction language for hybrid quantum/classical computing—and open-source python tools intended for building and running Quil programs.
By signing up for the service, both quantum computing researchers and scientists in other fields will get the chance to begin practicing how to write and test applications that will run on future quantum computers. And it’s likely that Rigetti hopes such researchers from various academic labs or companies could end up becoming official customers.
“We’re a full stack quantum computing company,” says Madhav Thattai, Rigetti’s chief strategy officer. “That means we do everything from design and fabrication of quantum chips to packaging the architecture needed to control the chips, and then building the software so that people can write algorithms and program the system.”
Much still has to be done before quantum computing becomes a practical tool for researchers and companies. Rigetti’s approach to universal quantum computing uses silicon-based superconducting qubits that can take advantage of semiconductor manufacturing techniques common in today’s computer industry. That means engineers can more easily produce the larger arrays of qubits necessary to prove that quantum computing can outperform classical computing—a benchmark that has yet to be reached.
Google researchers hope to demonstrate such “quantum supremacy” over classical computing with a 49-qubit chip by the end of 2017. If they succeed, it would be an “incredibly exciting scientific achievement,” Bestwick says. Rigetti Computing is currently working on scaling up from 8-qubit chips.
But even that huge step forward in demonstrating the advantages of quantum computing would not result in a quantum computer that is a practical problem-solving tool. Many researchers believe that practical quantum computing requires systems to correct the quantum errors that can arise in fragile qubits. Error correction will almost certainly be necessary to achieve the future promise of 100-million-qubit systems that could perform tasks that are currently impractical, such as cracking modern cryptography keys.
Though it may seem like quantum computing demands far-off focus, Rigetti Computing is complementing its long-term strategy with a near-term strategy that can serve clients long before more capable quantum computers arise. The quantum computing cloud service is one example of that. The startup also believes a hybrid system that combines classical computing architecture with quantum computing chips can solve many practical problems in the short term, especially in the fields of machine learning and chemistry. What’s more, says Rigetti, such hybrid classical/quantum computers can perform well even without error correction.
“We’ve uncovered a whole new class of problems that can be solved by the hybrid model,” Bestwick says. “There is still a large role for classical computing to own the shell of the problem, but we can offload parts of the problem that the quantum computing resource can handle.”
There is another tall hurdle that must be overcome before we’ll be able to build the quantum computing future: There are not many people in the world qualified to build a full-stack quantum computer. But Rigetti Computing is focused on being a full-stack quantum computing company that’s attractive to talented researchers and engineers who want to work at a company that is trying to take this field beyond the academic lab to solve real-world problems.
Much of Rigetti’s strategy here revolves around its Junior Quantum Engineer Program, which helps recruit and train the next generation of quantum computing engineers. The program, says Thattai, selects some of the “best undergraduates in applied physics, engineering, and computer science” to learn how to build full-stack quantum computing in the most hands-on experience possible. It’s a way to ensure that the company continues to feed the talent pipeline for the future industry.
On the client side, Rigetti is not yet ready to name its main customers. But it did confirm that it has partnered with NASA to develop potential quantum computing applications. Venture capital firms seem impressed by the startup’s near-term and long-term strategies as well, given news earlier this year that Rigetti had raised $64 million in series A and B funding led by Andreessen Horowitz and Vy Capital.
Whether it’s clients or investors, Rigetti has sought out like-minded people who believe in the startup’s model of preparing for the quantum computing future beyond waiting on the hardware.
“Those people know that when the technology crosses the precipice of being beyond what classical computing can do, it will flip very, very quickly in one generation,” Thattai says. “The winners and losers in various industries will be decided by who took advantage of quantum computing systems early.”