We demonstrate low-loss measurement of the hyperfine ground state of Rubidium atoms in a dipole trap array of five sites by state dependent fluorescence detection. The presence of atoms and their internal states are minimally altered by utilizing circularly polarized probe light and a strictly controlled quantization axis. We achieve mean state detection fidelity of 97% without correcting for imperfect state preparation or background losses, and 98.7% when corrected. After state detection and correction for background losses, the probability of atom loss due to the state measurement is <2% and the initial hyperfine state is preserved with >98% probability.
@article{arxiv.1706.09497,
title = {Parallel low-loss measurement of multiple atomic qubits},
author = {Minho Kwon and Matthew F. Ebert and Thad G. Walker and M. Saffman},
journal= {arXiv preprint arXiv:1706.09497},
year = {2017}
}