The crossing of stacking faults: This is an image of epitaxially grown ZnMgSe/ZnSe, which provides suitable single-photon sources and optically controllable qubits for quantum information technology. In this material, intrinsic and extrinsic stacking faults are found and form a crossing. Contributors: Xi Chen, Nils von den Driesch, Marvin Marco Jansen, Yurii Kutovyi, Alexander Pawlis, James LeBeau