Optically-active spin systems coupled to photonic cavities with high cooperativity can generate strong light-matter interactions, a key ingredient in quantum networks. But obtaining high cooperativities for quantum information processing often involves the use of photonic crystal cavities that feature a poor optical access from the free space, especially to circularly polarized light required for the coherent control of the spin. Here, we demonstrate coupling with cooperativity as high as 8 of an InAs/GaAs quantum dot to a fabricated bullseye cavity that provides nearly degenerate and Gaussian polarization modes for efficient optical accessing. We observe spontaneous emission lifetimes of the quantum dot as short as 80 ps (a ≈15 Purcell enhancement) and a ≈80% transparency of light reflected from the cavity. Leveraging the induced transparency for photon switching while coherently controlling the quantum dot spin could contribute to ongoing efforts of establishing quantum networks.
@article{arxiv.2111.13653,
title = {Optical transparency induced by a largely Purcell-enhanced quantum dot in a polarization-degenerate cavity},
author = {Harjot Singh and Demitry Farfurnik and Zhouchen Luo and Allan S. Bracker and Samuel G. Carter and Edo Waks},
journal= {arXiv preprint arXiv:2111.13653},
year = {2022}
}