Nonlinear dynamics of quantum dot nuclear spins

Coupling of a single confined electron-spin to a mesoscopic ensemble of nuclear spins defined by a quantum dot (QD) gives rise to rich physical phenomena such as non-Markovian electron-spin decoherence. It has been argued that controlling QD nuclear spins by carrying out either dynamical nuclear spin polarization (DNSP) or precise measurements of the effective nuclear magnetic field (Overhauser field) would prolong the electron spin coherence time and thereby enhance the prospects of implementing QD spin-based quantum information processing.The degree of DNSP in a QD can be determined by measuring the Overhauser field induced energy shift (the Overhauser shift) in the QD photoluminescence (PL). In this work, we study the magnetic field dependence of DNSP in a single self-assembled QD, located in a gated structure that allows for deterministic QD charging.