  Novel platforms interfacing trapped cold atoms and guided light in nanoscale
waveguides are a promising route to achieve a regime of strong coupling between
light and atoms in single pass, with applications to quantum non-linear optics
and quantum simulation. A strong challenge for the experimental development of
this emerging waveguide-QED field of research is to combine facilitated optical
access for atom transport, atom trapping via guided modes and robustness to
inherent nanofabrication imperfections. In this endeavor, here we propose to
interface Rubidium atoms with a photonic-crystal waveguide based on a
large-index GaInP slab. With a specifically tailored half-W1 design, we show
that a large chiral coupling to the waveguide can be obtained and guided modes
can be used to form two-color dipole traps for atoms at 116~nm from the edge of
the structure. This optimized device should greatly improve the level of
experimental control and facilitate the atom integration.
