Sub-ms, nondestructive, time-resolved quantum-state readout of a single, trapped neutral atom

Abstract

We achieve fast, nondestructive quantum-state readout via fluorescence detection of a single 87 Rb atom in the 5S 1/2 (F = 2) ground state held in an optical dipole trap. The atom is driven by linearly-polarized readout laser beams, making the scheme insensitive to the distribution of atomic population in the magnetic sub-levels. We demonstrate a readout fidelity of 97.6 ± 0.2% in a readout time of 160 ± 20 µs with the atom retained in > 97% of the trials, representing a substantial advance over other magnetic-state-insensitive techniques. We demonstrate that the F = 2 state is partially protected from optical pumping by a fortuitous distribution of the dipole matrix elements for the various transitions and the AC-Stark shifts from the optical trap. Our results are likely to find wide application in neutral-atom quantum computing and simulation.