Rostock 2019 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 42: Poster: Quantum Optics and Photonics II
Q 42.19: Poster
Wednesday, March 13, 2019, 16:15–18:15, S Atrium Informatik
Perspectives for a Photonic Quantum Gate Based on Cavity-Rydberg-EIT — •Thomas Stolz1, Valentin Walther2, Callum Robert Murray2, Thomas Pohl2, Steffen Schmidt-Eberle1, Lukas Husel1, Stephan Dürr1, and Gerhard Rempe1 — 1Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany — 2Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK 8000 Aarhus C, Denmark
We recently realized a photon-photon π-phase gate based on free-space Rydberg EIT in an ultra-cold atomic ensemble. [1] The performance in terms of efficiency and post-selected fidelity is limited by density dependent dephasing resulting from the interaction between the Rydberg electron and surrounding ground-state atoms. This effect becomes less prominent at low density where the presence of a ground-state atom inside the Rydberg orbit becomes unlikely. Reducing the atomic density in our present scheme would, unfortunately, make it difficult to maintain a π phase shift. Here, we investigate theoretically if better performance can be obtained by placing the ensemble inside an optical resonator. Previous literature has discussed this idea [2,3] but ignored imperfections resulting from dephasing, storage and retrieval, and optical components. Using realistic numbers for these imperfections, we identify optimal system parameters and estimate that the performance should profit drastically.
[1] D. Tiarks et al. Nat.Phys. (2018), doi:10.1038/s41567-018-0313-7
[2] Y. M. Hao et al. Sci. Rep. 5, 10005 (2015).
[3] S. Das et al. PRA 93, 040303 (2016).