QNS

This France-Canada collaborative project aims to advance knowledge, methods and applications for developing a quantum sensor network to spatially delocalized physical phenomena beyond the standard quantum limit due to the uncertainty principle and reach as close as possible to the ultimate quantum limit for metrology. A quantum sensor achieves exquisitely fine sensitivity by using quantum resources such as coherent and entanglement judiciously to channel quantum uncertainties away from the variable of interest to a variable not of interest, and a quantum sensor network combines quantum sensors in an array to be detect phenomena over a region of space. Quantum sensor networks are expected to have disruptive benefits for applications such as global positioning systems, timekeeping, and telescopes for probing the universe. The France collaborators analyse what kind of quantum resource such as entanglement or contextuality provides a quantum advantage to the sensor network and the Canadian collaborators use this knowledge to design a quantum clock network, which is a special case of quantum sensor networks, and to assess the efficacy of this network, for circumventing accepted limits of clock networks and to probe, eventually, gravitational waves, which cause fluctuations of space and time. Clocks are known to perform more poorly on the ocean compared to on land due to the action of waves on clocks placed on a boat, and the background of gravitational waves in the universe, due to phenomena such as the Big Bang, acts similarly on networks of clocks but in a relativistic way that mixes time and space effects together, and aspiration is to be able to sense and quantify these gravitational waves.