2015/01/31 by Y. -Y. Jau, A. M. Hankin, Tyler Keating +2 · 2 citations
Physics and Astronomy · #quant-ph #physics.atom-ph
paper · pdf · doi:10.1038/nphys3487
8 pages, 6 figures
arxiv created 2016/01/05 · arxiv updated 2016/01/07
Controlling quantum entanglement between parts of a many-body system is the key to unlocking the power of quantum information processing for applications such as quantum computation, high-precision sensing, and simulation of many-body physics. Spin degrees of freedom of ultracold neutral atoms in their ground electronic state provide a natural platform given their long coherence times and our ability to control them with magneto-optical fields, but creating strong coherent coupling between spins has been challenging. We demonstrate a Rydberg-dressed ground-state blockade that provides a strong tunable interaction energy (∼1 MHz in units of Planck's constant) between spins of individually trapped cesium atoms. With this interaction we directly produce Bell-state entanglement between two atoms with a fidelity ≥ 81(2)%, excluding atom loss events, and ≥ 60(3)% when loss is included.