Precise positioning of an ion in an integrated Paul trap-cavity system using radiofrequency signals

TL;DR

This paper introduces a miniature ion trap with integrated fibre cavity and radiofrequency control, enabling precise ion positioning for quantum networks without complex mechanical stages.

Contribution

The novel trap design allows three-dimensional ion positioning using RF electrodes, enhancing integration and precision in cavity quantum electrodynamics systems.

Findings

Successful coupling of ion to fibre cavity

Precise control of ion position limited only by ion's spatial spread

Demonstrated scalable and rigid trap design

Abstract

We report a novel miniature Paul ion trap design with an integrated optical fibre cavity which can serve as a building block for a fibre-linked quantum network. In such cavity quantum electrodynamic set-ups, the optimal coupling of the ions to the cavity mode is of vital importance and this is achieved by moving the ion relative to the cavity mode. The trap presented herein features an endcap-style design complemented with extra electrodes on which additional radiofrequency voltages are applied to fully control the pseudopotential minimum in three dimensions. This method lifts the need to use three-dimensional translation stages for moving the fibre cavity with respect to the ion and achieves high integrability, mechanical rigidity and scalability. Not based on modifying the capacitive load of the trap, this method leads to precise control of the pseudopotential minimum allowing the ion to be moved with precisions limited only by the ion's position spread. We demonstrate this by coupling the ion to the fibre cavity and probing the cavity mode profile.