Exchange interaction-driven dynamic nuclear polarization in Mn-doped InGaAs/GaAs quantum dots

The optical spin orientation and subsequent dynamic nuclear polarization (DNP) in individual self-assembled InGaAs/GaAs quantum dots doped by a single Mn atom is shown to be strongly perturbed by the exchange interaction between a photo-created electron and the spin of the magnetic impurity. The anisotropic part of the exchange, if strong enough, significantly depolarizes the electron spin in moderate magnetic fields, preventing thus any DNP. Yet, for small …

Coherent control of an artificial atom with few photons

In an optical quantum network, the information is transferred from one node to an other through light. A possible building block for such quantum network is an atom in a cavity. Ideally, every photon sent on the node should interact with the atom. Researchers at C2N, in collaboration with Institut Néel (Grenoble, France) have demonstrated the coherent control of an artificial atom with few photons. The quantum node …