  We have investigated how the Rayleigh-Plateau instability of a filament made
of a 41K-87Rb self-bound mixture may lead to an array of identical quantum
droplets, with typical breaking times which are shorter than the lifetime of
the mixture. If the filament is laterally confined -- as it happens in a
toroidal trap -- and atoms of one species are in excess with respect to the
optimal, equilibrium ratio, the droplets are immersed into a superfluid
background made by the excess species which provides global phase coherence to
the system, suggesting that the droplets array in the unbalanced system may
display supersolid character. This possibility has been investigated by
computing the non-classical translational inertia coefficient. The filament may
be a reasonable representation of a self-bound mixture subject to toroidal
confinement when the bigger circle radius of the torus is much larger than the
filament radius.
