Atoms near dielectric materials behave in a different way than in vacuum.
For instance, spontaneous emission rate or dipole-dipole interactions can
be severely modified by the presence of such a material. This can lead
to self-organization phenomena, in which the atoms are trapped in a potential
that they create themselves. One can also use photonic crystal structures to
design subwavelength optical lattices in two dimensions for ultracold atoms
by using guided modes and Casimir-Polder forces. Additionally, guided
modes can be used to induce large and long-range interactions between the
trapped atoms, giving rise a very promising platform for quantum simulations.