  The droplet crystal phase of a symmetric binary mixture of Rydberg-blockaded
dipolar Bose gases is studied by computer simulation. At high temperature each
droplet comprises on average equal numbers of particles of either component,
but the two components demix below the supersolid transition temperature, i.e.,
droplets mostly consist of particles of one component. Droplets consisting of
the same component will also favor clustering. Demixing is driven by quantum
tunnelling of particles across droplets over the system, and does not take
place in a non-superfluid crystal. This effect should be easily detectable in a
cold gas experiment.
