We demonstrate a new approach for fast preparation, manipulation, and collective readout of an atomic Rydberg-state qubit. By making use of Rydberg blockade inside a small atomic ensemble, we prepare a single qubit within 3~μs with a success probability of Fp=0.93±0.02, rotate it, and read out its state in 6μs with a single-shot fidelity of Fd=0.92±0.04. The ensemble-assisted detection is 103 times faster than imaging of a single atom with the same optical resolution, and enables fast repeated non-destructive measurement. We observe qubit coherence times of 15~μs, much longer than the π rotation time of 90~ns. Potential applications ranging from faster quantum information processing in atom arrays to efficient implementation of quantum error correction are discussed.
@article{arxiv.2105.11050,
title = {Fast Preparation and Detection of a Rydberg Qubit using Atomic Ensembles},
author = {Wenchao Xu and Aditya V. Venkatramani and Sergio H. Cantú and Tamara Šumarac and Valentin Klüsener and Mikhail D. Lukin and Vladan Vuletić},
journal= {arXiv preprint arXiv:2105.11050},
year = {2021}
}