The Innovative Training Network MoSaiQC has 15 open positions for PhD students, here called Early Stage Researchers (ESR). In all positions you will work in leading research groups and industry laboratories on projects at the forefront of a flourishing research field. You will address topics that range from fundamental insights (superradiant lasing, driven-dissipative or long-range interacting quantum systems, cavity QED,...) over crucial breakthroughs (continuous superradiant lasing, accurate frequency standards) to practical solutions (integrated optical clock).