Surface-electrode ion trap with integrated light source
Tony Hyun Kim, Peter F. Herskind, Isaac L. Chuang · Applied Physics Letters · 2011
An atomic ion is trapped at the tip of a single-mode optical fiber in a cryogenic (8 K) surface-electrode ion trap. The fiber serves as an integrated source of laser light, which drives the quadrupole qubit transition of S88r+. Through in situ translation of the nodal point of the trapping field, the Gaussian beam profile of the fiber output is imaged, and the fiber-ion displacement, in units of the mode waist at the ion, is optimized to within 0.13±0.10 of the mode center despite an initial offset of 3.30±0.10. Fiber-induced charging by 125 μW of 674 nm light is observed to be ∼10 V/m at an ion height of 670 μm, with charging and discharging time constants of 1.6±0.3 s and 4.7±0.6 s, respectively. This work is of importance to large-scale, ion-based quantum information processing, where optics integration in surface-electrode designs may be a crucial enabling technology.