  We present a new realization of asymmetric dark matter in which the dark
matter and lepton asymmetries are generated simultaneously through two-sector
leptogenesis. The right-handed neutrinos couple both to the Standard Model and
to a hidden sector where the dark matter resides. This framework explains the
lepton asymmetry, dark matter abundance and neutrino masses all at once. In
contrast to previous realizations of asymmetric dark matter, the model allows
for a wide range of dark matter masses, from keV to 10 TeV. In particular, very
light dark matter can be accommodated without violating experimental
constraints. We discuss several variants of our model that highlight
interesting phenomenological possibilities. In one, late decays repopulate the
symmetric dark matter component, providing a new mechanism for generating a
large annihilation rate at the present epoch and allowing for mixed warm/cold
dark matter. In a second scenario, dark matter mixes with the active neutrinos,
thus presenting a distinct method to populate sterile neutrino dark matter
through leptogenesis. At late times, oscillations and dark matter decays lead
to interesting indirect detection signals.
