  Solvation, the result of the complicated interplay between solvent-solute and
solvent-internal interactions, is one of the most important chemical processes.
Consequently, a complete theoretical understanding of solvation seems a heroic
task. However, it is possible to elucidate fundamental solvation mechanisms by
looking into simpler systems, such as ion solvation in atomic baths. In this
work, we study ion solvation by calculating the ground state properties of a
single ion in a neutral bath from the high-density regime to the low-density
regime, finding common ground for these two, in principle, disparate regimes.
Our results indicate that a single $^{174}$Yb$^+$ ion in a bath of $^{7}$Li
atoms forms a coordination complex at high densities with a coordination number
of 8, with strong electrostriction, characteristic of the snowball effect. On
the contrary, treating the atomic bath as a dilute quantum gas at low
densities, we find that the ion-atom interaction's short-range plays a
significant role in the physics of many-body bound states and polarons.
Furthermore, in this regime, we explore the role of a putative ion trap, which
drastically affects the binding mechanism of the ion and atoms from a quantum
gas. Therefore, our results give a novel insight into the universality of
ion-neutral systems in the ultracold regime and the possibilities of observing
exotic many-body effects.
