Optical Read-Out and Initialization of an Electron Spin in a Single Quantum Dot

We describe theoretically the resonant optical excitation of a trion with circularly polarized light and discuss how this trion permits the read-out of a single electron spin through a recycling transition. Optical pumping through combination of circularly polarized optical $\pi$--pulses with permanent or $\pi$-- pulsed transverse magnetic fields suggests feasible protocols for spin initialization.