Abstract: This disclosure relates to an integrated quantum information processing device with host chips having a body. Each body has a first surface, a second surface opposite the first surface, a defect cluster, and optical structures to direct excitation light that has entered the host chip toward the defect cluster and to direct fluorescent light emitted by the defect cluster to exit the host chip. A base chip has a first side coupled to the second surface of each host chip, a second side, an electromagnetic signal guiding structure to guide electromagnetic control signals toward the defect cluster. A magnetic field is aligned with a spin axis at a colour centre of the defect cluster and enables initialisation and readout of nuclear spin states of the colour centre. For each host chip the defect cluster is located proximate the respective second surface relative to the first surface.