  We describe one-dimensional photonic crystals that support a guided mode
suitable for atom trapping within a unit cell, as well as a second probe mode
with strong atom-photon interactions. A new hybrid trap is analyzed that
combines optical and Casimir-Polder forces to form stable traps for neutral
atoms in dielectric nanostructures. By suitable design of the band structure,
the atomic spontaneous emission rate into the probe mode can exceed the rate
into all other modes by more than tenfold. The unprecedented single-atom
reflectivity $r_0 \gtrsim 0.9$ for the guided probe field should enable diverse
investigations of photon-mediated interactions for 1D atom chains and cavity
QED.
