  Long range dipolar effects in 1D systems either in free or inhomogeneous
space are the basis of the state preparation protocol here proposed. Under the
presence of an external time-dependent magnetic field, dipole-dipole
interactions in the binary ultracold $^{166}$Er -$^{164}$Dy system were tuned
from repulsive to attractive to access either, the droplet regime, or the
extended one where individual species can be found in mixed or demixed phases.
A thorough exploration of weak contact and dipole-dipole effective interactions
parameters leads us to determine the phase diagrams of the 1D Bose clouds
affected by three different external fields; free homogeneous, harmonic, and
optical lattice confining potentials. These results were used to propose
long-life states composed of alternate assemblies of individual species
confined in optical lattices that mimics magnetic domains, whose size can be
adjusted. Our analysis based on numerical experiments within a mean field
scheme considered large enough systems as those commonly used in experimental
platforms.
