A network of clocks for measuring the stability of fundamental constants

We propose to create a world-leading programme to search for spatial and temporal variations of fundamental constants of nature, using a network of quantum clocks. Our consortium will build a community that will achieve unprecedented sensitivity in testing variations of the fine structure constant, alpha, and the proton-to-electron mass ratio, mu. This in turn will provide more stringent constraints on a wide range of fundamental and phenomenological theories beyond the Standard Model and on dark matter models. The ambition of the QSNET consortium will be enabled by a unique experimental platform that connects a number of complementary quantum sensors across the UK, namely state-of-the-art atomic clocks, molecular clocks, and a highly-charged ion clock. Key to the proposal is the networked approach in which clocks, with different sensitivities to changes of the fundamental constants, will be linked using optical fibres. The network involves a range of different quantum sensing devices and devices with different technology readiness levels: from the more established microwave atomic clocks on the one end to the highly-charged ion clock on the other. QSNET will be able to deliver important results in the first years, and at the same time develop advanced quantum sensors to provide increasingly impactful results as the project continues and the most sophisticated sensors come on line.