||Individual point defects in diamond crystals belong to an important class of quantum systems denoted as solid-state qubits. Such point defects, as for example NV, SiV, are intensively studied in the field of quantum sensing and metrology but also quantum information science. The applicants recently developed a novel technique, photoelectrically detected spin resonances in diamond, which brings promises for a new category of quantum devices that can be coupled with classical semiconducting electronics. The photoelectric readout is fundamentally based on charge state transitions in single point defects. In this respect, the photoelectric method differs from optical detection in two level quantum systems. In our proposal we would like to use this basic property of photoelectric readout and realise a novel type of qubit using the transition between the different charge state of the same defect. Combining with the spin manipulations a hybrid quantum systems can be conceived. The proposal is based on preliminary results demonstrating the SiV charge state readout. To devise the mechanism of charge state transitions we will use predictive ab initio calculations theoretical methodology, permitting to determine the energy position of charge state levels in the diamond gap, photoionisation cross section, rates and the electron transport coherence with respect to the driving field.