Submicrosecond entangling gate between trapped ions via Rydberg interaction

Zhang, Chi; Pokorny, Fabian; Hennrich, Markus; Li, Weibin; Lesanovsky, Igor; Higgins, Gerard; P�schl, Andreas

Abstract

© 2020, The Author(s), under exclusive licence to Springer Nature Limited. Generating quantum entanglement in large systems on timescales much shorter than the coherence time is key to powerful quantum simulation and computation. Trapped ions are among the most accurately controlled and best isolated quantum systems1 with low-error entanglement gates operated within tens of microseconds using the vibrational motion of few-ion crystals2,3. To exceed the level of complexity tractable by classical computers the main challenge is to realize fast entanglement operations in crystals made up of many ions (large ion crystals)4. The strong dipole–dipole interactions in polarmolecule5 and Rydbergatom6,7 systems allow much faster entangling gates, yet stable state-independent confinement comparable with trapped ions needs to be demonstrated in these systems8. Here we combine the benefits of these approaches: we report a two-ion entangling gate with 700-nanosecond gate time that uses the strong dipolar interaction between trapped Rydberg ions, which we use to produce a Bell state with 78 per cent fidelity. The sources of gate error are identified and a total error of less than 0.2 per cent is predicted for experimentally achievable parameters. Furthermore, we predict that residual coupling to motional modes contributes an approximate gate error of 10−4 in a large ion crystal of 100 ions. This provides a way to speed up and scale up trapped-ion quantum computers and simulators substantially.

Citation

Zhang, C., Pokorny, F., Hennrich, M., Li, W., Lesanovsky, I., Higgins, G., & Pöschl, A. (2020). Submicrosecond entangling gate between trapped ions via Rydberg interaction. Nature, 580(7803), 345-349. https://doi.org/10.1038/s41586-020-2152-9

• Journal Article Type: Article
• Acceptance Date: Jan 27, 2020
• Online Publication Date: Apr 15, 2020
• Publication Date: Apr 15, 2020
• Deposit Date: Jan 27, 2020
• Publicly Available Date: Oct 16, 2020
• Journal: Nature
• Print ISSN: 0028-0836
• Electronic ISSN: 1476-4687
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 580
• Issue: 7803
• Pages: 345-349
• DOI: https://doi.org/10.1038/s41586-020-2152-9
• Keywords: Multidisciplinary
• Public URL: https://nottingham-repository.worktribe.com/output/3810774
• Publisher URL: https://www.nature.com/articles/s41586-020-2152-9
• Additional Information: Received: 29 August 2019; Accepted: 27 January 2020; First Online: 15 April 2020; : The authors declare no competing interests.