Fiber optics in surface ion traps for scalable quantum information processing*

Fiber optics can provide a more scalable and resource efficient means of delivering light to and collecting fluorescence from a trapped ion than bulk optics. We demonstrate trapping of a $^ {24}$Mg$^+$ ion in a gold-on-quartz surface-electrode Paul trap with an integrated high numerical-aperture multi-mode fiber located 50 $\mu$m below the electrode surface, and observe fluorescence photons through the fiber with a collection numerical aperture of 0.37. The trap features multiple RF electrodes whose potentials can be adjusted to vary the height of the pseudopotential zero from 30 to 50 $\mu$m above the electrode surface (80 to 100 $\mu$m from the fiber). This demonstrates the ability to trap and position ions near dielectrics, an important step toward trapping ions in fiber optic microcavities.