  Quantum states of light and matter can be manipulated on the nanoscale to
provide a technological resource for aiding the implementation of scalable
photonic quantum technologies [1-3]. Experimental progress relies on the
quality and efficiency of the coupling between photons and internal states of
quantum emitters [4-6]. Here we demonstrate a nanophotonic waveguide platform
with embedded quantum dots (QDs) that enables both Purcell-enhanced emission
and strong chiral coupling. The design uses slow-light effects in a glide-plane
photonic crystal waveguide with QD tuning to match the emission frequency to
the slow-light region. Simulations were used to map the chirality and Purcell
enhancement depending on the position of a dipole emitter relative to the air
holes. The highest Purcell factors and chirality occur in separate regions, but
there is still a significant area where high values of both can be obtained.
Based on this, we first demonstrate a record large radiative decay rate of 17
ns^-1 (60 ps lifetime) corresponding to a 20 fold Purcell enhancement. This was
achieved by electric-field tuning of the QD to the slow-light region and
quasi-resonant phonon-sideband excitation. We then demonstrate a 5 fold Purcell
enhancement for a dot with high degree of chiral coupling to waveguide modes,
substantially surpassing all previous measurements. Together these demonstrate
the excellent prospects for using QDs in scalable implementations of on-chip
spin-photonics relying on chiral quantum optics.
