Microsoft’s Majorana 1 widened the quantum field. But are we any closer to a eureka moment?

Quantum researchers are in a race for qubits, and Microsoft is in the thick of the competition.

Microsoft has spent the last 20 years pursuing a topological approach to quantum development. Last week, they had a breakthrough: The company counted eight topological qubits on their Majorana 1 chip. They published a paper in Nature, got a glowing New York Times piece about a “new state of matter,” and buoyed quantum stocks across the market. 

Eight qubits isn’t anywhere near what would be needed to reach full-scale quantum computing. That number is in the millions, and they would need to be error-corrected. Other companies, like IBM and Google, are much further ahead on that—just with different models. Microsoft finally proved that the topological approach could work; now, they’ve got to catch up. (Think of it like discovering a new way to build a car engine: Microsoft just got theirs to start, while others are already racing down the track.) There are reasons to be excited—namely, that a topological approach could be less susceptible to noise—but they’re still vastly behind in scale. 

“If anybody believes this means that Microsoft is close to a commercial quantum computer, they’re missing the point,” says Alan Baratz, CEO of D-Wave Quantum, a rival quantum company. “It’s a validation that [topological] is a viable approach. Will it be a better approach than superconducting or trapped ion or photonic or neutral atom? That remains to be seen.”

The many paths to quantum computing

All of our computers operate using “bits,” the smallest unit of digital information. This bit can be either a zero or a one. Quantum researchers are now developing bits that can be both zero and one at the same time—something that would dramatically speed up computations. These “qubits” are difficult to develop, even harder to scale, and almost impossible to correct for errors. Still, researchers at major companies have made significant progress. 

But there’s not one singular way to build a qubit. The most prominent approach to making a qubit relies on superconducting circuits—Google, IBM, and Amazon Web Services have all bet big on that. Another is the photonic technique, which uses light particles as qubits; that’s being developed domestically by PsiQuantum and Xanadu, and overseas by Chinese researcher Jian-Wei Pan. Each has shown promise, but most still face major hurdles, keeping large-scale, error-corrected quantum computing years away.

Microsoft has added a topological approach to the rat race. “[For other modalities], we’ve demonstrated the physics as a community. Now it’s about scale,” says Jack Hidary, CEO of AI company SandboxAQ. “In the case of topological, it’s the one modality that needed a fundamental science breakthrough.” 

But, while Microsoft has reached their “science breakthrough,” other companies have pushed further. Both Hidary and Baratz reference Google’s Willow chip, which employs the superconducting approach. Not only did Willow employ significantly more qubits, but it also proved that error-correction was scalable. The more qubits, Google found, the more they reduced error. 

“They were able to show partial error correction on gate model qubits for the first time, and that’s critically important,” Baratz says. “That’s a true advance. I think [Majorana 1] is just a proof of concept widening.”

Baratz is, like a number of physicists, generally skeptical of the Microsoft announcement. He references Microsoft’s previous failure in the arena: After publishing a 2018 paper in Nature claiming a Majorana discovery, quantum researchers began to question their findings. Microsoft’s scientists admitted “insufficient scientific rigour” in 2021, and Nature retracted the paper. Baratz also notes that the paper ignored qubit or gate fidelity, both measures of accuracy. “It leads you to wonder, what is this chip actually capable of doing, and to what extent is it actually a process?” he asks. 

For their part, Microsoft is embracing the spirit of competition. “Others are working to bring this same vision to life, but with different approaches,” a Microsoft spokesperson wrote in an email to Fast Company. “This is what makes science fun. Some in the field believe an alternative approach is the right one to take and have invested significant time and resources into their methods. We understand why they would want to advocate for their approach. Discourse and skepticism are all part of the scientific process.”

Still, there’s a reason scientists continue to call Microsoft’s paper a “breakthrough.” While the company may not have anything close to a quantum computer—or even a lead in the race to get there—they’ve pulled off something thought previously unimaginable. Most had simply given up on the topological approach.

“The topological approach is the most scientifically daunting approach to building a quantum computer, and that’s why Microsoft deserves credit,” Hidary says. “Kudos.” 

How far are we from full-scale, marketable quantum computing? That’s still unknown. But experts like Karthee Madasmy, who was an early investor in PsiQuantum, thinks the Microsoft news is yet another good sign. The timeline has shrunk, he says. 

“It’s not multiple decades away,” Madasmy says. “It’s actually a few years away.” 

View the full article