2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/22131We consider electron spin qubits in quantum dots and define a measurement efficiency e to characterize reliable measurements via n-shot read outs. We propose various implementations based on a double dot and quantum point contact (QPC) and show that the associated efficiencies e vary between 50% and 100%, allowing single-shot read out in the latter case. We model the read out microscopically and derive its time dynamics in terms of a generalized master equation, calculate the QPC current and show that it allows spin read out under realistic conditions.5 pages, 1 figureMesoscale and Nanoscale PhysicsQuantum Physicstext