QSNET, A network of clocks for measuring the stability of fundamental constants

I will discuss the QSNET project, which is building a network of atomic and molecular clocks in the UK to achieve unprecedented sensitivity to testing variations of the fine-structure constant, α, and the electron-to-proton mass ratio, μ. This in turn will allow us to either discover that fundamental constants are actually not constant, or to provide more stringent constraints on a wide range of fundamental and phenomenological “new physics” models. These include models of dark energy, ultra-light dark matter and grand unification models. The project currently includes several atomic clocks (Sr, Yb+, Cs) at the National Physical Laboratory, a molecular ion clock (N2+) at the University of Sussex, a molecular lattice clock (CaF) at Imperial College London, and a highly charged ion clock (Xe, Cf) at the University of Birmingham. I will present the latest developments and results from the network, including a new method for detecting gravitational waves in the milli-Hz band.