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 …

Near optimal single photon sources in the solid-state

Researchers at C2N, in collaboration with Institut Néel (Grenoble, France) and University of Queensland (Australia), have fabricated single photon sources based on semiconductor quantum dots of unprecedented quality. They succeeded in combining a unique technique invented in 2008 to position a quantum dot at the center of a micropillar acting as an optical cavity and an electrical control to remove the charge noise. They demonstrated the controlled …