"We propose to create and detect quantum entanglement between a single spin in the solid state and a single photon and in a second step entanglement between two distant spins. This experiment will be realized using Nitrogen-Vacancy (NV) centers in diamond, that are exceptionally well suited for this due to their very long spin coherence time and a strong and stable optical transition that allows spin-photon mapping. An NV center in a superposition of spin states will be optically excited, and the subsequently spontaneously emitted photon will have a frequency that is entangled with the NV center’s spin. This entanglement will be detected using correlation measurements, and thus requires high-fidelity coherent control and readout of single spins. Entanglement of distant spins will be realized via interference of indistinguishable photons originating from two distant NV centers. Successful generation of long-distance entanglement constitutes a milestone challenge for quantum information processing in the solid state. The proposed experiment combines state-of-the art methods from quantum optics, magnetic resonance and nanofabrication and provides an excellent opportunity for the researcher to deepen and diversify his experimental skills. This training will allow the researcher to reach professional maturity and carry out an independent line of research."