Towards High-Rate Quantum Repeaters Using Fiber-based Micromirror Cavities and Trapped Ions

Photon collection efficiences are currently a primary limitation on remote entanglement rates with trapped ions. Higher rates could be achieved using fiber-based optical cavities for light collection, which can support a small mode volume and can couple the emitted photon into an optical fiber with minimal loss. However, experiments involving ions trapped near the large dielectric surfaces that comprise short optical cavities have thus far suffered from large, drifting stray fields and high ion motional heating rates. Here I discuss progress towards trapping an ion inside a fiber-based optical cavity integrated with a surface electrode trap at cryogenic temperatures. I specifically discuss measurements of the stray fields and ion motional heating rates induced by a cryogenic, bare optical fiber positioned hundreds of microns from an ion, and progress towards making high-finesse optical cavities with microfabricated mirrors directly attached and mode-matched into single mode optical fibers.