CONTROL AND MANIPULATION OF SINGLE ATOMS FOR INTERFACING WITH LIGHT

Abstract

An efficient atom-light coupling is indispensable for a future distributed quantum network. To achieve this objective, we investigate a free-space atom-light interface based on a high numerical aperture lens. In our experimental setup, we employ aspheric lenses (NA=0.75) to tightly focus light onto optically trapped single 87Rb atoms. We first study the Mollow triplet phenomenon in the fluorescence spectra for increasing power levels. We then present several experimental techniques aimed at preserving qubit coherence, minimizing atomic temperature, and scaling up the number of qubits. Dynamical decoupling sequences extend the coherence time of a superposition state to 7 ms. Additionally, we demonstrate the cooling of atomic motion to less than 6 μK using the Fano interference effect. Finally, we show loading of single atoms into a pair of holographic dipole traps spaced 3 µm apart. The tools developed in this work pave way for the implementation of practical quantum information protocols.