  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.
