  Alkaline-earth-metal atoms exhibit long-range dipolar interactions, which are
generated via the coherent exchange of photons on the 3P_0-3D_1-transition of
the triplet manifold. In case of bosonic strontium, which we discuss here, this
transition has a wavelength of 2.7 \mu m and a dipole moment of 2.46 Debye, and
there exists a magic wavelength permitting the creation of optical lattices
that are identical for the states 3P_0 and 3D_1. This interaction enables the
realization and study of mixtures of hard-core lattice bosons featuring
long-range hopping, with tuneable disorder and anisotropy. We derive the
many-body Master equation, investigate the dynamics of excitation transport and
analyze spectroscopic signatures stemming from coherent long-range interactions
and collective dissipation. Our results show that lattice gases of
alkaline-earth-metal atoms permit the creation of long-lived collective atomic
states and constitute a simple and versatile platform for the exploration of
many-body systems with long-range interactions. As such, they represent an
alternative to current related efforts employing Rydberg gases, atoms with
large magnetic moment, or polar molecules.
