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Abstract:

We present an original scheme to rotate at will one electron-spin trapped in a quantum dot by just acting on a pump-laser polarization: The quantum control is based on the virtual excitation of electron light-holes pairs with p-symmetry, as possibly done by using a single laser beam with a propagation axis slightly tilted with respect to a weak magnetic field. The relative effect of this magnetic field is beautifully increased at will by just acting on the photon polarization. This allows us to fully control the effective axis of the electron-spin rotation through the pump polarization. Our analysis shows that quantum dots with inverted valence states are ideal candidates for ultra-fast, high-fidelity, all optical control.