Fast Ground State Manipulation of Neutral Atoms in Microscopic Optical Traps

We demonstrate Rabi flopping at MHz rates between ground hyperfine states of neutral ⁸⁷Rb atoms that are trapped in two micron sized optical traps. Using tightly focused laser beams we demonstrate high fidelity, site specific Rabi rotations with cross talk on neighboring sites separated by 8 μm at the level of 10^-3. Ramsey spectroscopy is used to measure a dephasing time of 870 μs, which is ≈5000 times longer than the time for a π/2 pulse.