The quantum advantage: a novel demonstration

Is a quantum machine really more efficient than a conventional machine for performing calculations? Demonstrating this ‘advantage’ experimentally is particularly complex and a major research challenge around the world1 . Scientists from the CNRS2 , the University of Edinburgh (Scotland) and the QC Ware, Corp., (France and USA) have just proved that a quantum machine can perform a given verification task in seconds when the same exercise would take a time equivalent to the age of the universe for a conventional computer. For this demonstration, they combined a complex interactive algorithm that solves a certain type of mathematical problem with limited information and a simple experimental photonics system that can be made in all advanced photonics laboratories. Their work was published on 8 February 2021 in Nature Communications.

• 1In 2019, Google achieved the first demonstration of this type when it sampled from random quantum circuits on their Sycamore chip, made of 53 superconducting qubits. Very recently, Chinese researchers have shown a quantum advantage with boson sampling using an elaborate photonic configuration.
• 2At the LIP6 Laboratory (CNRS/Sorbonne University) and the Institut de Recherche en Informatique Fondamentale (CNRS/University of Paris).