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

Abstract

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.