# Ion induced density bubble in a strongly correlated one dimensional gas - Condensed Matter > Quantum Gases

Abstract: We consider a harmonically trapped Tonks-Girardeau gas of impenetrable bosonsin the presence of a single embedded ion, which is assumed to be tightlyconfined in a RF trap. In an ultracold ion-atom collision the ion-s chargeinduces an electric dipole moment in the atoms which leads to an attractive$r^{-4}$ potential asymptotically. We treat the ion as a static deformation ofthe harmonic trap potential and model its short range interaction with the gasin the framework of quantum defect theory. The molecular bound states of theionic potential are not populated due to the lack of any possible relaxationprocess in the Tonks-Girardeau regime. Armed with this knowledge we calculatethe density profile of the gas in the presence of a central ionic impurity andshow that a density \textit{bubble} of the order of a micron occurs around theion for typical experimental parameters. From these exact results we show thatan ionic impurity in a Tonks gas can be described using a pseudopotential,allowing for significantly easier treatment.

Author: J. Goold, H. Doerk, Z. Idziaszek, T. Calarco, Th. Busch

Source: https://arxiv.org/