Abstract
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 short range of the ion-atom interaction
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.