High-fidelity parallel entangling gates on a neutral-atom quantum computer

• Published in: Nature (London) 2023-10, Vol.622 (7982), p.268-272
• Main Authors: Evered, Simon J., Bluvstein, Dolev, Kalinowski, Marcin, Ebadi, Sepehr, Manovitz, Tom, Zhou, Hengyun, Li, Sophie H., Geim, Alexandra A., Wang, Tout T., Maskara, Nishad, Levine, Harry, Semeghini, Giulia, Greiner, Markus, Vuletić, Vladan, Lukin, Mikhail D.
• Format: Article
• Language: English
• Subjects: 639/766/483/2802; 639/766/483/481; Accuracy; Benchmarks; Calibration; Computers; Connectivity; Error correction; Gates; Humanities and Social Sciences; Lasers; Methods; multidisciplinary; Optical pumping; Quantum computers; Qubits (quantum computing); Science; Science & Technology - Other Topics; Science (multidisciplinary); Temperature effects
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-023-06481-y

The ability to perform entangling quantum operations with low error rates in a scalable fashion is a central element of useful quantum information processing 1 . Neutral-atom arrays have recently emerged as a promising quantum computing platform, featuring coherent control over hundreds of qubits 2 , 3 and any-to-any gate connectivity in a flexible, dynamically reconfigurable architecture 4 . The main outstanding challenge has been to reduce errors in entangling operations mediated through Rydberg interactions 5 . Here we report the realization of two-qubit entangling gates with 99.5% fidelity on up to 60 atoms in parallel, surpassing the surface-code threshold for error correction 6 , 7 . Our method uses fast, single-pulse gates based on optimal control 8 , atomic dark states to reduce scattering 9 and improvements to Rydberg excitation and atom cooling. We benchmark fidelity using several methods based on repeated gate applications 10 , 11 , characterize the physical error sources and outline future improvements. Finally, we generalize our method to design entangling gates involving a higher number of qubits, which we demonstrate by realizing low-error three-qubit gates 12 , 13 . By enabling high-fidelity operation in a scalable, highly connected system, these advances lay the groundwork for large-scale implementation of quantum algorithms 14 , error-corrected circuits 7 and digital simulations 15 . The realization of two-qubit entangling gates with 99.5% fidelity on up to 60 rubidium atoms in parallel is reported, surpassing the surface-code threshold for error correction and laying the groundwork for neutral-atom quantum computers.