Erasure conversion in a high-fidelity Rydberg quantum simulator

Abstract

Minimizing and understanding errors is critical for quantum science, both in noisy intermediate scale quantum (NISQ) devices^ 1 and for the quest towards fault-tolerant quantum computation^ 2 , 3 . Rydberg arrays have emerged as a prominent platform in this context^ 4 with impressive system sizes^ 5 , 6 and proposals suggesting how error-correction thresholds could be significantly improved by detecting leakage errors with single-atom resolution^ 7 , 8 , a form of erasure error conversion^ 9 – 12 . However, two-qubit entanglement fidelities in Rydberg atom arrays^ 13 , 14 have lagged behind competitors^ 15 , 16 and this type of erasure conversion is yet to be realized for matter-based qubits in general. Here we demonstrate both erasure conversion and high-fidelity Bell state generation using a Rydberg quantum simulator^ 5 , 6 , 17 , 18 . When excising data with erasure errors observed via fast imaging of alkaline-earth atoms^ 19 – 22 , we achieve a Bell state fidelity of $$\ge 0.997{1}_{-13}^{+10}$$ ≥ 0.997 1 − 13 + 10 , which improves to $$\ge 0.998{5}_{-12}^{+7}$$ ≥ 0.998 5 − 12 + 7 when correcting for remaining state-preparation errors. We further apply erasure conversion in a quantum simulation experiment for quasi-adiabatic preparation of long-range order across a quantum phase transition, and reveal the otherwise hidden impact of these errors on the simulation outcome. Our work demonstrates the capability for Rydberg-based entanglement to reach fidelities in the 0.999 regime, with higher fidelities a question of technical improvements, and shows how erasure conversion can be utilized in NISQ devices. These techniques could be translated directly to quantum-error-correction codes with the addition of long-lived qubits^ 7 , 22 – 24 . Erasure conversion and detection are used in a Rydberg quantum simulator to create Bell states with high fidelity, competitive with other state-of-the-art platforms.