Quantum Logic with Trapped Molecular Ions

Dipole-dipole interactions between closely-trapped polar molecules have long been proposed for quantum information processing with neutral molecules.  This paper explores an extension of this idea to trapped molecular ions.  The apparent challenge of polarizing the ions in the lab frame (since they are ions, a static field does not work since it will simply accelerate them out of the trap) is circumvented by using oscillating dipole moments ("transition dipoles") instead of static moments.  The ions maintain their orientation and we show that the quantum logic is surprisingly robust.  More information can be found here.