Whatever happens, the Majorana drama is a setback for Microsoft’s ambitions to compete in quantum computing. Big IT companies say technology will define the future by enabling new breakthroughs in science and engineering.
Quantum computers are built from devices called qubits that encode 1s and 0s of data, but can also use a quantum state called superposition to perform math tricks not possible for bits in a conventional computer. The main challenge in commercializing this idea is that quantum states are delicate and easily canceled by thermal or electromagnetic noise, making qubits prone to error.
Google, IBM, and Intel have all showcased prototypes of quantum processors with around 50 qubits, and companies such as Goldman Sachs and Merck are testing the technology. But thousands or millions of qubits are probably needed for useful work. Much of the power of a quantum computer should probably be devoted to correcting its own problems.
Microsoft has taken a different approach, claiming that Majorana particle-based qubits will be more scalable, allowing it to take a leap forward. But after more than a decade of work, he doesn’t have a single qubit.
Majorana fermions are named after the Italian physicist Ettore Majorana, who hypothesized in 1937 that particles should exist with the strange property of being their own antiparticles. Shortly after, he boarded a ship and was never seen again. Physicists wouldn’t bring back a good glimpse of one of its eponymous particles until the next millennium, in the Kouwenhoven laboratory.
Microsoft took an interest in Majoranas after company researchers in 2004 approached chief technology officer Craig Mundie and said they had a way to fix an issue holding quantum computers back: the fragility of qubits.
Researchers grabbed theoretical physics papers suggesting a way to build qubits that would make them more reliable. These so-called topological qubits would be built around unusual particles, of which Majorana particles are an example, which can appear in clusters of electrons inside certain materials at very low temperatures.
Microsoft has created a new team physicists and mathematicians to flesh out the theory and practice of topological quantum computing, centered on an outpost in Santa Barbara, Calif., dubbed Station Q. They collaborated with and funded leading experimental physicists to research the particles needed to build this new form of qubit.
Kouwenhoven, in Delft, was one of the physicists to gain support from Microsoft. His 2012 article reporting “signaturesMajorana particles inside the nanowires began to discuss a future Nobel Prize for proving the existence of the elusive particles. In 2016, Microsoft stepped up its investment and hype.
Kouwenhoven and another prominent physicist Charles Marcus from the University of Copenhagen were hired as Majorana corporate hunters. The plan was to detect the particles first and then invent more complex devices that could control them and function as qubits. Todd Holmdahl, who previously ran hardware for Microsoft’s lucrative Xbox game console, took the lead on the topological quantum computing project. At the start of 2018, he Told Barron’s it would have a topological qubit by the end of the year. The now disputed newspaper appeared a month later.
While Microsoft researched Majoranas, competitors working on established qubit technologies reported steady progress. In 2019, Google announced it had reached a milestone called quantum supremacy, showing that a 53-qubit chip could perform a statistical computation in minutes that would take a millennial supercomputer. Soon after, Microsoft appeared to cover up its quantum bet, announcing that it would. provide access to quantum hardware other businesses through its Azure cloud service. The Wall Street Journal reported Holmdahl left the project that year after missing an internal deadline.
Microsoft has been quieter about its expected pace of progress on quantum hardware since Holmdahl’s departure. Competitors in quantum computing continue to tout hardware advancements and urge software developers to access prototypes on the internet, but none seem close to creating a quantum computer ready for prime time.