  We analyze the coupling of atoms or atom-like emitters to nanophotonic
waveguides in the presence of propagating acoustic waves. Specifically, we show
that strong index modulations induced by such waves can drastically modify the
effective photonic density of states and thereby influence the strength, the
directionality, as well as the overall characteristics of photon emission and
absorption processes. These effects enable a complete dynamical control of
light-matter interactions in waveguide structures, which even in a two
dimensional system can be used to efficiently exchange individual photons along
selected directions and with a very high fidelity. Such a quantum
acousto-optical control provides a versatile tool for various quantum
networking applications ranging from the distribution of entanglement via
directional emitter-emitter interactions to the routing of individual photonic
quantum states via acoustic conveyor belts.
