Individual-qubit readout is a key ingredient for quantum simulation and quantum computation. Furthermore, this readout must take place in real-time to enable the application of quantum error-correction protocols. In this paper the capability of an EMCCD camera with a real-time processing capable output is demonstrated to determine the quantum state of a single 9Be+ ion and the required timing sequences are explored. The results are comparable to a PMT based detection. Experiments on the individual detection of 9Be+ qubit states undergoing coherent excitation are reported. Sources of error and the amount of crosstalk in the detection system are discussed. Error rates due to known problems in the state preparation and measurement processes were determined to be approximately 0.5 %.
@article{arxiv.2204.09112,
title = {Real-time capable CCD-based individual trapped-ion qubit measurement},
author = {S. Halama and T. Dubielzig and N. Orlowski and C. Torkzaban and C. Ospelkaus},
journal= {arXiv preprint arXiv:2204.09112},
year = {2022}
}