Power of quantum computer tested online

The French start-up Quandela brought together, during a hackathon, students and researchers to solve problems using a machine that works with photonic “qubits”. A European advance that competes with the Americans and the British.

by David Larousserie

They were the first to test a quantum computer available remotely, a unique machine in Europe. About sixty young international students and researchers had this chance on the Sorbonne University campus in Paris, from November 7 to 9. This technology promises to carry out certain calculations more quickly than the most efficient of the superordinators, or even to solve problems inaccessible today.

Several companies, IBM, Microsoft, Google, Amazon, Rigetti, D-Wave … already offer prototypes of such machines, but whose performance remains very far from promises. To this list, we must now add the French start-up Quandela. Born in 2017, it launched its quantum processor online on November 15, the first in Europe outside the United Kingdom.

 The source of unique photons from Quandela with a piece of optical fiber allowing to transport the light to a quantum calculation chip. The source of unique photons from Quandela with a piece of optical fiber allowing to transport the light to a quantum calculation chip. Matt la prod

“On weekend before this hackathon at the Sorbonne, I was sitting in my sofa, and from my laptop, I could launch a calculation that would have put Three months of focusing in my laboratory. I was not coming back! “Said Pascale Sénellart, research director at the CNRS, and co -founder of Quandela. The day before, on Friday evening, her husband Jean, director of the company’s software engineering, was still in the process of tinning the updates with her team. And on Monday, quantum computer apprentices from Spain, Portugal, Germany, Netherlands and France, could program and launch the machine.

Massive parallelization of operations

This one, called Ascella, is installed 15 kilometers away, in Massy (Essonne), in the premises of the start-up. It holds in a black metal piece of furniture, large as a fridge, which evokes the installations of data centers. A regular noise chants the seconds and betrays the operation of a pump that circulates helium in order to cool to -260 ° C an essential part of the computer: the source from which will be called what are called ” qubits “. This suitcase word, contraction of quantum and bits, is the key to the power of these machines. In a classic computer, the information is stored with 0 or 1, the bits. In it, and in its counterparts, it is possible to be 0 and 1 at a time, and even any combination of the two. This allows in a way a massive parallelization of operations, by exploring a set of possibilities at once, rather than blow.

These qubits can be individual atoms trapped, or superconductive electronic mini-circuits, or, like here, photons, the particles constituting light. The source of Quandela thus sends 80 million unique photons per second, after excitation by a laser radius of a nanoscopic sandwich of semiconductive layers. It is already sold to research laboratories and even competitors.

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/Media reports cited above.