Majorana 1: What Microsoft's Announcement Means for the Future of Quantum Computers

In a dramatic announcement, Microsoft revealed on Wednesday that it has created the first quantum chip based on topological qubits , a special type of qubit based on particles called Majorana Fermions. The new Quantum Processing Unit, dubbed “Majorana 1” in honor of the Italian physicist, is a prototype built with the first “topoconductor,” a special superconductor capable of hosting “quasiparticles” that exist in the “topological” state of matter and exploiting them to conduct quantum operations.

The Advantage of Topological Qubits Unlike other qubits more commonly used in quantum computers by Google, IBM, Rigetti and many others, topological qubits are much more difficult to realize because they presuppose the creation of a new state of matter: Microsoft itself has been trying for at least twenty years.

However, at least in theory, they have a fundamental advantage over the others: they are extremely more resistant to the degradation of their quantum state - necessary to conduct calculations - due to the very way they work. Compared to other qubits, they are essentially much more "robust" and resistant to errors already at the hardware level, thus eliminating the need for a huge effort to correct errors at the software level.

This is because the “topological” state is characterized by properties that, unlike the liquid, solid and gaseous states, do not depend on the local characteristics of the material (such as the atomic arrangement), but on global, fixed properties linked to its mathematical structure.

If confirmed, Microsoft's result could pave the way for the creation of new quantum chips that are much more stable and controllable, thus shortening the road to quantum computers capable of revolutionizing computing from a couple of decades to a few years. The Majorana 1 chip, according to Microsoft, already contains 8 of these qubits. Experts agree that for true supremacy in quantum computing and to obtain valid commercial applications, chips with at least a million qubits are needed.

The ability to limit errors at the physical level, Microsoft says, could allow computing power to scale to these levels much more easily, since it does not require an error correction system applied to each qubit, typical of other “non-topological” approaches.

“You don’t get to a million qubits without blood, sweat, and tears, and without solving a lot of very difficult technical challenges along the way,” Chetan Nayak, a technical fellow at Microsoft and leader of the team experimenting with the topological approach, told MIT Technology Review. “They’re not trying to downplay the challenges that lie ahead, but we do have a visual on the goal.”

How much marketing and how much science? However, as always in these cases, it is necessary to separate the wheat of applied science from the chaff of scientific marketing. In particular, it remains to be clarified why the statements of the CEO of Microsoft and the press release, which clearly speak of a “new state of matter,” and the content of the scientific article published in Nature at the same time as the announcement seem to tell two different stories.

“Microsoft has a top-notch scientific team that produces first-rate results,” Professor Tommaso Calarco, a quantum physicist and professor at the University of Bologna, explains to Italian.Tech. “However, I wonder how the CEO’s statement came about, because from what we can read in Nature there is still no certainty that what was measured is actually a topological qubit. From Microsoft’s statements, however, it seems certain that the result has been obtained.”

The crux of the matter is this: Microsoft's announcement talks about the creation of the first topological qubit and therefore presupposes that the research teams have managed to "synthesize" (pardon the simplification) a Majorana fermion, correctly measuring its existence and quantum state (Majorana Zero Mode) inside the topological superconductor created by Microsoft "atom on atom" using aluminum and indium arsenide.

What the Nature article really says The article published in Nature, however, focuses on the measurement approach and does not yet “prove” the existence of quasiparticles in the superconductor, but claims to have obtained a fundamental result in the system to verify their existence.

“In this paper,” Nature reports, “we demonstrate the possibility of a time-resolved measurement, thereby validating a fundamental ingredient of topological quantum computation.”

“In the article the researchers say this: we have succeeded in an operation that is fundamental for our purposes,” Calarco explains. “In itself, this scientific result is already extraordinary and of the highest level. However, they also admit that this measurement at the moment does not confirm whether the measured phenomenon is actually connected to the presence of Majorana fermions, or whether it is instead a trivial and therefore non-topological phenomenon.”

The real smoking gun is in the editorial notes to the article, also in Nature, where the reviewers of the paper warn about the interpretation of the paper: “The editorial team wishes to emphasize that the results of this manuscript do not represent a proof of the presence of Majorana Zero Modes ( the quantum state relevant to obtain topological qubits - ed .) in the reported devices. The work is published to introduce a device architecture that could enable future experiments of fusion with Majorana Zero Modes”.

The precedents between Microsoft and Nature Nature's extreme caution is most likely due to Microsoft's precedents and the "scandal" that in 2021 led to the retraction of an article on the same topic co-authored by researchers affiliated with the Redmond company and Delft University of Technology. In 2018, Nature published an article in which the research team claimed to have observed convincing evidence of the presence of Majorana Zero Modes (MZMs) in superconducting nanowires. This study was considered one of the strongest evidence for the existence of MZMs and strengthened the idea that Microsoft was on the right track to building a topological quantum computer. However, three years later, one of the researchers involved discovered discrepancies in the calculations. Further investigation revealed that some data had been selected in order to emphasize the desired signal, while ignoring others that cast doubt on the discovery.

Microsoft's Response Chetan Nayak, the head of the research group, responded to the wave of skepticism with a comment on the blog of Scott Aaronson , an American professor and computer scientist known for his popularization work in the field of quantum computing. "Readers of the Nature article will probably have noticed that the paper was submitted for review on March 5, 2024, and published on February 19, 2025. Over the past year, we have continued to make progress," explains Nayak, adding several technical details that confirm the measurement of at least four Majorana Zero Modes and therefore the topological nature of Microsoft's qubits.

There is a fundamental problem, however: these results, which have clearly informed Microsoft's public celebrations, cannot yet be considered "peer reviewed" and therefore must inevitably be taken with a pinch of salt. As Aaronson explains, "the situation is that Microsoft unequivocally claims to have created a topological qubit and has just published a relevant paper in Nature, but the claim of having created a topological qubit has not yet been accepted by Nature's peer review." Huge investments

In short, there is a good chance that Microsoft has actually achieved what it claims, including the “creation of a new state of matter”. However, the scientific certainty of a peer-reviewed article is missing, which the company clearly did not want to wait for before announcing the new discovery with great fanfare. “If everything were confirmed and were scalable as Microsoft claims, we would certainly be faced with a sensational discovery that opens the way to new applications,” Calarco concludes. “However, if we are to stick to what we read in Nature, for now the mountain has given birth to the proverbial mouse. Let's not forget that this research, however, requires huge investments that must be justified - even internally within large companies. It is inevitable that in the communication of these results there is also a fundamental aspect of scientific marketing”.