Starting on May 1, 2026, a new Research Training Group at LUH will create a scientific bridge between the two clusters of excellence, QuantumFrontiers and PhoenixD. Colleagues from the Institutes of Solid State Physics, Photonics, Gravitational Physics, and Theoretical Physics are collaborating on the fundamentals of quantum states of the light field for photonic applications in quantum communication, quantum cryptography, and quantum computing. The Research Training Group aims for a solid-state-based hybrid quantum photonics with tailored control of complex quantum states. The first funding period will run until April 30, 2031, with two cohorts of ten doctoral students each supported by the DFG. The spokesperson for the Research Training Group is Michael Oestreich from the Institute of Solid State Physics.