In an oxide apertured quantum dot (QD) micropillar cavity-QED system, we found strong QD hysteresis effects and lineshape modifications even at very low intensities corresponding to less than 0.001 intracavity photons. We attribute this to the excitation of charges by the intracavity field; charges that get trapped at the oxide aperture, where they screen the internal electric field and blueshift the QD transition. This in turn strongly modulates light absorption by cavity QED effects, eventually leading to the observed hysteresis and lineshape modifications. The cavity also enables us to observe the QD dynamics in real time, and all experimental data agrees well with a power-law charging model. This effect can serve as a novel tuning mechanism for quantum dots.
@article{arxiv.1503.08142,
title = {Quantum dot nonlinearity through cavity-enhanced feedback with a charge memory},
author = {Morten P. Bakker and Thomas Ruytenberg and Wolfgang Loffler and Ajit V. Barve and Larry Coldren and Martin P. van Exter and Dirk Bouwmeester},
journal= {arXiv preprint arXiv:1503.08142},
year = {2015}
}