Toronto startup Xanadu Quantum Technologies, one of several companies trying to harness the ephemeral nature of quantum physics to revolutionize the computer industry, has achieved an elusive feat with a device that could outperform any supercomputer in the world at a specific task.
In a paper published Wednesday in the research journal Nature, the company described how its hardware, a quantum computer called Borealis, achieved “quantum advantage” — a term meaning it provided a result beyond the practical scope of a conventional computer system.
Specifically, Borealis presented a series of numbers with a specific range of possibilities at just 36 millionths of a second, a process that would take the world’s most powerful supercomputers more than 9,000 years. This feat did not have immediate application, but the scholars at Xanadu had to overcome several major challenges to achieve it.
“This is what we think is really cool about this,” Christian Widbrock, founder and CEO of Xanadu, said during an interview at the company’s headquarters, where the Borealis is located on the 29th floor of an office building overlooking downtown Toronto. “A lot of these hacks are what we need to get into a quantum computer that’s useful to customers.”
He said the achievement “planted science for Canada” in the race to develop what’s known as a global quantum computer – a system that could be used in the future to bring down computational barriers in areas as diverse as cybersecurity, drug discovery, materials science, financial risk modeling and climate change mitigation.
The company has also invited outside users – from expert researchers to just the curious – to test Borealis online.
As with previous cases where quantum advantage has been demonstrated, a clever use of conventional computers may emerge that can simulate a quantum system – a tactic known in the field as spoofing.
However, Barry Sanders, director of the Institute for Quantum Science and Technology at the University of Calgary, said that what matters most about what Xanadu has done is that it reinforces the view that the industry is on its way to global quantum computing.
It’s not a small step, it’s a big leap forward,” said Dr. Sanders, who is not affiliated with Xanadu.
To the novice eye, Borealis looks more like a science experiment than a computer. It consists of optical fibers, mirrors and other components to direct the light scattered over the table top, with electronics supported on the shelves above. Its operating elements are pulses of compressed light – infrared laser light that has been manipulated to show certain quantum properties.
As the pulses travel through the system, some are sent in long, winding paths that allow them, at three points, to turn back and interact with the pulses that follow. These increasingly entangled pulses act as qubits of the system — similar to the ones and zeros in a conventional computer, but more diverse because their quantum weirdness allows them to hold a mixture of values that collectively solve the task.
This approach, known as photonics, has the advantage of being able to operate at room temperature. One drawback is that some light is inevitably lost as it travels through optical devices. But other types of quantum computers have their own trade-offs.
The first system to demonstrate the quantum advantage, which Google revealed in 2019, used cryo-cooled superconducting circuits as qubits. One year later, researchers at the University of Science and Technology in China claimed a quantum advantage using a light-based system. Neither of them crossed the 100 kbit threshold.
In contrast, Borealis is a 216 kbit device with features its designers say will allow them to scale more easily. (Another Canadian company, D-Wave Systems Inc., has reached the level of thousands of qubits with a non-universal form of quantum computing applicable to a narrower class of problems.)
Experts estimate that it would take at least a million qubits to make a commercially relevant quantum computer. This is because most of those qubits will be necessary to debug errors that infiltrate any quantum system. Like previous systems that have shown a quantitative advantage, the Borealis system does not include error correction in its design, an obstacle the field has not yet cleared.
The system was designed and assembled during the height of the COVID-19 pandemic, with team members working together online to work out the details of its operation, said Jonathan Lavoie, who led development of the Borealis system for Xanadu.
Its debut comes as the company is in the midst of raising $100 million, led by Toronto-based Georgian Growth Co., in a deal that values Xanadu at $1 billion, The Globe reported last month. Other investors in Xanadu include US fund Bessemer Venture Partners and Tiger Global Management LLC, Canadian billionaire Jeff Scholl, US venture capitalist Tim Draper, BDC Capital and the US Central Intelligence Agency’s venture capital arm In-Q-Tel.
Georgian lead investor Margaret Wu said Xanadu was “incredibly efficient at capital” and made more headway after raising and spending less money than competitors in the quantum computing space. She said Xanadu has continued to exceed internal expectations and “they’ve come a long way than we expected when we originally invested, and they’ve done so while preserving cash” during the pandemic.
“It’s great that they have been able to stay on the right track and continue to stay ahead of so many other approaches out there,” said Ms. Wu.
As quantum technology has advanced, investor interest has also increased, although the industry is still far from offering a commercially viable device. Research firm Gartner has predicted that nearly 40 percent of large companies will continue quantum initiatives by 2025.
Stephanie Simmons, founder and chief quantum officer of Coquitlam, Photonic Inc. British Columbia-based Quantum Technology: “This is the commercialization of the branch of physics that will eventually completely redefine everything, but it will take time.”
For now, the industry is in what Gartner analyst Girag Dickett has described as an embryonic state at best.
Many quantum computer developers, including Xanadu, have clients and research partners that include giants such as Volkswagen AG and Amazon.com Inc. , but most of the work these developers do is experimental and exploratory.
Dr Arne Christian Voigt, Head of the Innovative Technologies and Innovation Group with Volkswagen, which has conducted research projects using quantum machines from Xanadu, D-Wave Systems, Google and IonQ Inc.
Dr Voigt called Xanadu’s achievement “a very important step for optical quantum computing,” but said it was “an open question” whether any quantum computer could live up to the hype. “At the moment, it’s open what kind of technology will work later.”