What happened to the Majorana particle with which Microsoft intended to revolutionize quantum computing
The Majorana fermion has been an elusive particle for decades. The Italian physicist Ettore Majorana theoretically predicted its existence in 1937, and since then many researchers have become obsessed with it because it has a characteristic that makes it unique: it is both a particle and its own antiparticle.
When a particle comes into contact with its antiparticle, both are destroyed in a process that causes the release of a lot of energy. This could happen, for example, to an electron and a positron, which is the antiparticle of the electron. However, and this is what is really surprising, the Majorana particle play in another league.
A candy for quantum computing
During the last decades particle physicists have achieved know better the peculiarities of the Majorana particles. In fact, several scientific articles have come to light, such as the one published in the journal Science by a group of researchers from Princeton University in 2019, which propose ingenious methods to characterize, manipulate and preserve these particles.
From a theoretical point of view, Majorana particles could be involved in the manufacture of higher quality qubits than those used in current quantum computers.
What makes them very attractive for quantum computing is that, when they appear, in theory they do it in pairs and they have a reasonably high stability, something that is not abundant in the world of particles subjected to the laws of quantum mechanics.
Physicists soon realized that the link between each pair of Majorana particles could be harnessed to store quantum information in two different places.
This duplication, together with the relative stability of these particles, suggests that they could be involved in the manufacture of more stable qubits and less prone to external disturbances than the qubits used in today’s quantum computers.
Tune up higher quality qubits is one of the great challenges that quantum computing has ahead, and some physicists argue that these particles are the ingredient we need to get them.
The group of researchers led by the Dutch physicist Leo Kouwenhoven, from the QuTech research center (the Netherlands), which is co-financed by Microsoft, published in March 2018 an article in the prestigious scientific journal Nature in which he described several experiments that, according to them, had allowed them to identify those so elusive up to that moment fermiones de Majorana. The news had a huge repercussion and it heralded good times for quantum computing.
The latest scientific article is disheartening
Shortly after the publication of the article, some scientists who were also doing research in the field of quantum computing showed reasonable doubts about what the group led by Kouwenhoven claimed. One of them was the physicist Sergey Frolov, from the University of Pittsburgh, who thought that in the article relevant data was missing that threw some inconsistency about Kouwenhoven’s work.
The authors later told us it was done for aesthetics. We have a problem with this. The segments where data jumps off plateau (magenta) or where ‘Majorana’ peak splits (green) were aesthetically cut off. But 7 charge switches prolonging the plateau were kept (yellow). Convenient? pic.twitter.com/Izjl1FtDyr
— Sergey Frolov (@spinespresso) February 3, 2021
From that moment on, the shadow of doubt fell on the work of the Dutch physicist and on the strategy that should allow Microsoft to obtain higher quality qubits for your future quantum computer. And the worst forecasts have been confirmed only a few days ago. A new article Published by Kouwenhoven’s group at the end of last January, it demolishes what they themselves announced in 2018.
In this recent publication, these researchers expose more data about the conditions in which they carried out the experiments they described in their original article, and conclude that the evidence by which they believed they had identified these fermions they were wrong. The article they originally published in Nature is going to be amended.
It is a pity that in the end this investigation did not turn out well, but this does not diminish the potential interest which seems to have the application of the Majorana particle in quantum computing. We will keep track of you and tell you more when we have new information.
More information | Cornell University