We report on the feedback stabilization of the zero-phonon emission frequency of a single InAs quantum dot. The spectral separation of the phonon-assisted component of the resonance fluorescence provides a probe of the detuning between the zero-phonon transition and the resonant driving laser. Using this probe in combination with active feedback, we stabilize the zero-phonon transition frequency against environmental fluctuations. This protocol reduces the zero-phonon fluorescence intensity noise by a factor of 22 by correcting for environmental noise with a bandwidth of 191 Hz, limited by the experimental collection efficiency. The associated sub-Hz fluctuations in the zero-phonon central frequency are reduced by a factor of 7. This technique provides a means of stabilizing the quantum dot emission frequency without requiring access to the zero-phonon emission.
@article{arxiv.1410.4728,
title = {Frequency stabilization of the zero-phonon line of a quantum dot via phonon-assisted active feedback},
author = {Jack Hansom and Carsten H. H. Schulte and Clemens Matthiesen and Megan Stanley and Mete Atature},
journal= {arXiv preprint arXiv:1410.4728},
year = {2015}
}