  In the development of atomic, molecular and optical (AMO) physics, atom-ion
hybrid systems are characterized by the presence of a new tool in the
experimental AMO toolbox: atom-ion interactions. One of the main limitations in
state-of-the-art atom-ion experiments is represented by the micromotion
component of the ions' dynamics in a Paul trap, as the presence of micromotion
in atom-ion collisions results in a heating mechanism that prevents atom-ion
mixtures from undergoing a coherent evolution. Here we report the design and
the simulation of a novel ion trapping setup especially conceived for the
integration with an ultracold atoms experiment. The ion confinement is realized
by using an electro-optical trap based on the combination of an optical and an
electrostatic field, so that no micromotion component will be present in the
ions' dynamics. The confining optical field is generated by a deep optical
lattice created at the crossing of a bow-tie cavity, while a static electric
quadrupole ensures the ions' confinement in the plane orthogonal to the optical
lattice. The setup is also equipped with a Paul trap for cooling the ions
produced by photoionization of a hot atomic beam, and the design of the two ion
traps facilitates the swapping of the ions from the Paul trap to the
electro-optical trap.
