Jörg Müller's Quantum Metrology group works on next-generation optical atomic clocks and superradiant lasers. Key experiments: cold strontium continuous superradiant laser (subnatural linewidth, pushing beyond traditional clock limitations); microresonator-based frequency combs; ultra-stable optical reference cavities; and cavity QED many-atom systems for clocks and sensing. The group is part of the EU iqClock project targeting operational optical lattice clocks.